Use WTF::CString instead (which until recently was WebCore::CString).

Reviewed by Geoff Garen.

JavaScriptCore: 

* JavaScriptCore.exp:
* JavaScriptCore.vcproj/JavaScriptCore/JavaScriptCore.def:
* runtime/UString.cpp:
* runtime/UString.h:

JavaScriptGlue: 

* ForwardingHeaders/wtf/text: Added.
* ForwardingHeaders/wtf/text/CString.h: Added.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@56864 268f45cc-cd09-0410-ab3c-d52691b4dbfc