CppTools/QmlJSEditor: Hide "Preserve Case" for Replace Symbol Under Cursor

...since it does not make sense for symbols.

Task-number: QTCREATORBUG-11669
Change-Id: Ic249cb15cdb3b324a9b215323acd802a33797100
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@digia.com>
CppTools: Save some stats by using correct include paths

..while initial parsing.

Change-Id: I202da3f4f9e445a28e9726352fc005488efe2893
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>