Added Cocoa-exact width measurement emulation flag to support IFStringTruncator.

    Remove code that was already conditionally excluded calls to support
    non-specified advance drawing (we now depend on tweaked advances).

	* Misc.subproj/IFStringTruncator.m:
	(+[IFStringTruncator centerTruncateString:toWidth:withFont:]):
	* WebCoreSupport.subproj/IFTextRenderer.h:
	* WebCoreSupport.subproj/IFTextRenderer.m:
	(-[IFTextRenderer initWithFont:]):
	(-[IFTextRenderer drawCharacters:length:atPoint:withColor:]):
	(-[IFTextRenderer slowFloatWidthForCharacters:length:applyRounding:]):
	(-[IFTextRenderer slowFloatWidthForCharacters:length:]):
	(-[IFTextRenderer floatWidthForCharacters:length:applyRounding:]):
	(-[IFTextRenderer floatWidthForCharacters:length:]):
	(-[IFTextRenderer extendCharacterToGlyphMapToInclude:]):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@1329 268f45cc-cd09-0410-ab3c-d52691b4dbfc