* Add SemanticHighlighter to QmlJSTextEditor to update the semantic info
  in a background thread.
* Add QmlJS::Check to run semantic checks on qml and js documents.
* Add a check for incorrect property names.
* Fix hoverhandler to show tool tips from extra selections over help
  tooltips.

It is used to evaluate expressions to values.
Done to make room for a real 'check' pass.

Reviewed-by: Roberto Raggi <qtc-committer@nokia.com>

	modified:   src/libs/qmljs/qmljsinterpreter.cpp

Reviewed-by: Roberto Raggi

Done-with: ckamm

* Support for lookup JS vs Qml
* Bind global variables.

Done-with: ckamm

Done-with: Roberto

Done with ckamm

We should never look at the scope chain of the base object when performing a dependant lookup.

Done-with: Roberto Raggi

Done-with: Christian Kamm