Reviewed by darin
        
        <rdar://problem/5046875> 
        Gmail Editor: Applying alignment to selected text in message also applies alignment to signature

        Added:
        * editing/style/5046875-1-expected.checksum: Added.
        * editing/style/5046875-1-expected.png: Added.
        * editing/style/5046875-1-expected.txt: Added.
        * editing/style/5046875-1.html: Added.
        * editing/style/5046875-2-expected.checksum: Added.
        * editing/style/5046875-2-expected.png: Added.
        * editing/style/5046875-2-expected.txt: Added.
        * editing/style/5046875-2.html: Added.
        moveParagraphs doesn't move unnecessary brs:
        * editing/style/create-block-for-style-002-expected.txt:
        * editing/style/create-block-for-style-004-expected.txt:
        * editing/style/create-block-for-style-001-expected.txt:
        * editing/style/create-block-for-style-009-expected.txt:
        * editing/style/create-block-for-style-010-expected.txt:
        moveParagraphs clears out unrendered text during the move:
        * editing/style/create-block-for-style-011-expected.txt:
        * editing/style/create-block-for-style-007-expected.txt:
        * editing/style/create-block-for-style-012-expected.txt:

WebCore:

        Reviewed by darin
        
        <rdar://problem/5046875> 
        Gmail Editor: Applying alignment to selected text in message also applies alignment to signature

        * editing/ApplyStyleCommand.cpp:
        (WebCore::ApplyStyleCommand::doApply): Don't call applyBlockStyle unless
        there is a block style to apply.
        (WebCore::ApplyStyleCommand::applyBlockStyle): Don't do the remove step.
        It was unnecessary and removed properties from blocks that could contain 
        content outside the range being operated on (added a testcase).
        (WebCore::ApplyStyleCommand::addBlockStyleIfNeeded): Used an early return
        instead of if-nesting.
        * editing/ApplyStyleCommand.h:
        * editing/CompositeEditCommand.cpp:
        (WebCore::CompositeEditCommand::moveParagraphContentsToNewBlockIfNecessary):
        Return the new block, if one was created.  Use moveParagraphs to move
        paragraphs into the new block, instead of moving nodes.  The old code moved
        too much (added a testcase).
        * editing/CompositeEditCommand.h:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@20181 268f45cc-cd09-0410-ab3c-d52691b4dbfc