Add an MathMLSelectElement class to implement <maction> and <semantics>.

Add an MathMLSelectElement class to implement <maction> and <semantics>.
<https://webkit.org/b/120058>

Patch by Frédéric Wang <fred.wang@free.fr> on 2013-12-03
Reviewed by Chris Fleizach.

Source/WebCore:

Tests: mathml/presentation/maction-dynamic.html
       mathml/presentation/maction.html
       mathml/presentation/semantics.html

This adds a new MathMLSelectElement class to prepare the implementation
of the <maction> and <semantics> elements, for which only one "selected"
child is visible. We now simply display the first child of the
<semantics> element instead of hiding the annotations and this allows to
handle the use case of SVG-in-MathML as generated by Instiki when
bug 124128 is fixed ; Gecko's selection algorithm will be implemented
later (bug 100626). We now also rely on the @actiontype and @selection
attributes to select the visible <maction> child ; It remains to deal
with the user interaction (bug 85734).

* CMakeLists.txt: add the new files.
* GNUmakefile.list.am: ditto
* Target.pri: ditto
* WebCore.vcxproj/WebCore.vcxproj: ditto
* WebCore.vcxproj/WebCore.vcxproj.filters: ditto
* WebCore.xcodeproj/project.pbxproj: ditto
* css/mathml.css: remove the CSS rule for annotation/annotation-xml.
* mathml/MathMLAllInOne.cpp: add the new cpp file.
* mathml/MathMLSelectElement.cpp: Added.
(WebCore::MathMLSelectElement::MathMLSelectElement):
(WebCore::MathMLSelectElement::create):
(WebCore::MathMLSelectElement::createRenderer):
(WebCore::MathMLSelectElement::childShouldCreateRenderer):
(WebCore::MathMLSelectElement::finishParsingChildren):
(WebCore::MathMLSelectElement::childrenChanged):
(WebCore::MathMLSelectElement::attributeChanged):
(WebCore::MathMLSelectElement::updateSelectedChild): basic implementation for maction, semantics, maction@actiontype and maction@selection.
* mathml/MathMLSelectElement.h: Added.
* mathml/mathattrs.in: add actiontype and selection attributes.
* mathml/mathtags.in: set element classes for maction, semantics, annotation and annotation-xml.

LayoutTests:

New tests for the selection of the visible child in the <maction> and <semantics> elements.

* mathml/presentation/maction-dynamic-expected.html: Added.
* mathml/presentation/maction-dynamic.html: Added.
* mathml/presentation/maction-expected.html: Added.
* mathml/presentation/maction.html: Added.
* mathml/presentation/semantics-expected.html: Added.
* mathml/presentation/semantics.html: Added.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@160005 268f45cc-cd09-0410-ab3c-d52691b4dbfc