Test cases added: Existing tab-related basic editing tests were updated.  More complex tests are coming soon.

        <rdar://problem/3792529> REGRESSION (Mail): Tabs do not work the way they did in Panther (especially useful in plain text mail)

        Basic strategy is to put tabs into spans with white-space:pre style, and
        render them with tabs stops every 8th space, where the space width and
        the left margin are those of the enclosing block.

        * khtml/editing/apply_style_command.cpp:
        (khtml::ApplyStyleCommand::removeCSSStyle):
        (khtml::ApplyStyleCommand::addInlineStyleIfNeeded):
        * khtml/editing/delete_selection_command.cpp:
        (khtml::DeleteSelectionCommand::saveTypingStyleState):
        * khtml/editing/edit_command.cpp:
        (khtml::EditCommand::styleAtPosition):
        * khtml/editing/html_interchange.h:
        * khtml/editing/htmlediting.cpp:
        (khtml::isSpecialElement):
        (khtml::isTabSpanNode):
        (khtml::isTabSpanTextNode):
        (khtml::positionBeforeTabSpan):
        (khtml::createTabSpanElement):
        * khtml/editing/htmlediting.h:
        * khtml/editing/insert_text_command.cpp:
        (khtml::InsertTextCommand::prepareForTextInsertion):
        (khtml::InsertTextCommand::input):
        (khtml::InsertTextCommand::insertTab):
        * khtml/editing/insert_text_command.h:
        * khtml/editing/markup.cpp:
        (khtml::createParagraphContentsFromString):
        (khtml::createFragmentFromText):
        * khtml/editing/replace_selection_command.cpp:
        (khtml::ReplacementFragment::removeStyleNodes):
        * khtml/html/htmltokenizer.cpp:
        (khtml::HTMLTokenizer::begin):
        (khtml::HTMLTokenizer::processListing):
        (khtml::HTMLTokenizer::parseSpecial):
        (khtml::HTMLTokenizer::parseText):
        (khtml::HTMLTokenizer::parseEntity):
        (khtml::HTMLTokenizer::parseTag):
        (khtml::HTMLTokenizer::addPending):
        (khtml::HTMLTokenizer::write):
        * khtml/html/htmltokenizer.h:
        (khtml::HTMLTokenizer::):
        * khtml/rendering/bidi.cpp:
        (khtml::addRun):
        (khtml::RenderBlock::tabWidth):
        (khtml::RenderBlock::computeHorizontalPositionsForLine):
        (khtml::RenderBlock::layoutInlineChildren):
        (khtml::RenderBlock::skipWhitespace):
        (khtml::RenderBlock::findNextLineBreak):
        (khtml::RenderBlock::checkLinesForTextOverflow):
        * khtml/rendering/break_lines.cpp:
        (khtml::isBreakable):
        * khtml/rendering/font.cpp:
        (Font::drawHighlightForText):
        (Font::drawText):
        (Font::floatWidth):
        (Font::floatCharacterWidths):
        (Font::checkSelectionPoint):
        (Font::width):
        * khtml/rendering/font.h:
        * khtml/rendering/render_block.cpp:
        (khtml:::RenderFlow):
        (khtml::RenderBlock::setStyle):
        (khtml::stripTrailingSpace):
        (khtml::RenderBlock::calcInlineMinMaxWidth):
        * khtml/rendering/render_block.h:
        * khtml/rendering/render_br.h:
        (khtml::RenderBR::width):
        * khtml/rendering/render_flexbox.cpp:
        (khtml::RenderFlexibleBox::layoutVerticalBox):
        * khtml/rendering/render_image.cpp:
        (RenderImage::setPixmap):
        (RenderImage::paint):
        * khtml/rendering/render_line.cpp:
        (khtml::EllipsisBox::paint):
        * khtml/rendering/render_line.h:
        (khtml::InlineBox::width):
        (khtml::InlineBox::xPos):
        (khtml::InlineBox::yPos):
        (khtml::InlineBox::height):
        (khtml::InlineBox::baseline):
        * khtml/rendering/render_list.cpp:
        (RenderListMarker::paint):
        (RenderListMarker::calcMinMaxWidth):
        * khtml/rendering/render_object.cpp:
        (RenderObject::tabWidth):
        (RenderObject::recalcMinMaxWidths):
        * khtml/rendering/render_object.h:
        * khtml/rendering/render_replaced.cpp:
        * khtml/rendering/render_text.cpp:
        (InlineTextBox::selectionRect):
        (InlineTextBox::paint):
        (InlineTextBox::paintSelection):
        (InlineTextBox::paintMarkedTextBackground):
        (InlineTextBox::textPos):
        (InlineTextBox::offsetForPosition):
        (InlineTextBox::positionForOffset):
        (RenderText::cacheWidths):
        (RenderText::widthFromCache):
        (RenderText::trimmedMinMaxWidth):
        (RenderText::calcMinMaxWidth):
        (RenderText::containsOnlyWhitespace):
        (RenderText::width):
        * khtml/rendering/render_text.h:
        * kwq/KWQFontMetrics.h:
        * kwq/KWQFontMetrics.mm:
        (QFontMetrics::width):
        (QFontMetrics::charWidth):
        (QFontMetrics::floatWidth):
        (QFontMetrics::floatCharacterWidths):
        (QFontMetrics::checkSelectionPoint):
        (QFontMetrics::boundingRect):
        (QFontMetrics::size):
        * kwq/KWQPainter.h:
        * kwq/KWQPainter.mm:
        (QPainter::drawRect):
        (QPainter::drawLine):
        (QPainter::drawText):
        (QPainter::drawHighlightForText):
        (_fillRectXX):
        (QPainter::fillRect):
        * kwq/WebCoreTextRenderer.h:
        * kwq/WebCoreTextRendererFactory.mm:
        (WebCoreInitializeEmptyTextStyle):
        * layout-tests/editing/deleting/delete-tab-001-expected.txt:
        * layout-tests/editing/deleting/delete-tab-001.html:
        * layout-tests/editing/deleting/delete-tab-002-expected.txt:
        * layout-tests/editing/deleting/delete-tab-002.html:
        * layout-tests/editing/deleting/delete-tab-003-expected.txt:
        * layout-tests/editing/deleting/delete-tab-003.html:
        * layout-tests/editing/deleting/delete-tab-004-expected.txt:
        * layout-tests/editing/deleting/delete-tab-004.html:
        * layout-tests/editing/inserting/insert-tab-001-expected.txt:
        * layout-tests/editing/inserting/insert-tab-002-expected.txt:
        * layout-tests/editing/inserting/insert-tab-003-expected.txt:
        * layout-tests/editing/inserting/insert-tab-004-expected.txt:
        * layout-tests/fast/js/string-replace-2-expected.txt:
        * layout-tests/fast/table/039-expected.txt:
        * layout-tests/fast/table/border-collapsing/004-expected.txt:
        * layout-tests/fast/tokenizer/script_extra_close-expected.txt:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@9963 268f45cc-cd09-0410-ab3c-d52691b4dbfc