Bug 844457 - Move XSLTProcessor to WebIDL. r=peterv

--HG--
rename : dom/xslt/nsIXSLTProcessor.idl => dom/webidl/XSLTProcessor.webidl
rename : dom/xslt/xml/txXMLUtils.cpp => dom/xslt/base/txExpandedName.cpp
rename : dom/xslt/xml/txXMLUtils.h => dom/xslt/base/txExpandedName.h