<https://bugs.webkit.org/show_bug.cgi?id=119829> Add IAccessibleText and IAccessibleEditableText interfaces and implementation to AppleWin port.

Reviewed by Chris Fleizach.

* AccessibleBase.cpp:
(AccessibleBase::createInstance): Create an AccessibleText instance when necessary.
(AccessibleBase::QueryService):
* AccessibleBase.h:
* AccessibleTextImpl.cpp: Added.
(AccessibleText::AccessibleText):
(AccessibleText::addSelection):
(AccessibleText::get_attributes): Not Implemented
(AccessibleText::get_caretOffset):
(AccessibleText::get_characterExtents):
(AccessibleText::get_nSelections):
(AccessibleText::get_offsetAtPoint):
(AccessibleText::get_selection):
(AccessibleText::get_text):
(AccessibleText::get_textBeforeOffset): Not Implemented
(AccessibleText::get_textAfterOffset): Not Implemented
(AccessibleText::get_textAtOffset): Not Implemented
(AccessibleText::removeSelection):
(AccessibleText::setCaretOffset):
(AccessibleText::setSelection):
(AccessibleText::get_nCharacters):
(AccessibleText::scrollSubstringTo):
(AccessibleText::scrollSubstringToPoint):
(AccessibleText::get_newText): Not Implemented
(AccessibleText::get_oldText): Not Implemented
(AccessibleText::get_attributeRange): Not Implemented
(AccessibleText::copyText):
(AccessibleText::deleteText):
(AccessibleText::insertText):
(AccessibleText::cutText):
(AccessibleText::pasteText):
(AccessibleText::replaceText):
(AccessibleText::setAttributes): Not Implemented
(AccessibleText::QueryInterface):
(AccessibleText::Release):
(AccessibleText::convertSpecialOffset):
(AccessibleText::initialCheck):
* AccessibleTextImpl.h: Added.
(AccessibleText::~AccessibleText):
(AccessibleText::AddRef):
* WebKit.vcxproj/Interfaces/Interfaces.vcxproj:
* WebKit.vcxproj/Interfaces/Interfaces.vcxproj.filters:
* WebKit.vcxproj/WebKit/WebKit.vcxproj:
* WebKit.vcxproj/WebKit/WebKit.vcxproj.filters:
* WebKit.vcxproj/WebKitGUID/WebKitGUID.vcxproj:
* WebKit.vcxproj/WebKitGUID/WebKitGUID.vcxproj.filters:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@154627 268f45cc-cd09-0410-ab3c-d52691b4dbfc