Fixed <rdar://problem/4885131> Move CFString function declarations from 
        JSStringRef.h to JSStringRefCF.h
        
        Also removed remaining API FIXMEs and changed them into Radars.

        * API/JSClassRef.cpp:
        (OpaqueJSClass::OpaqueJSClass): Added Radar numbers for UTF8 conversion.

        * API/JSContextRef.cpp:
        (JSGlobalContextCreate): Replaced FIXME for NULL JSContextRef with Radar number.

        * API/JSObjectRef.h: Removed FIXME, which is unprofessional in a public header.

        * API/JSStringRef.cpp: Moved CF related implementations to JSStringRefCF.cpp.
        (JSStringCreateWithUTF8CString): Replaced FIXME with Radar number.
        * API/JSStringRef.h: Moved CF related declarations to JSStringRefCF.h. Added
        #include of JSStringRefCF.h as a stopgap until clients start #including
        it as needed by themselves.

        * API/JSStringRefCF.cpp: Added.
        (JSStringCreateWithCFString):
        (JSStringCopyCFString): Replaced JSChar cast with UniChar cast, which is 
        more appropriate for a CF call.
        * API/JSStringRefCF.h: Added.
        * JavaScriptCore.xcodeproj/project.pbxproj:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@19059 268f45cc-cd09-0410-ab3c-d52691b4dbfc