And made the warnings/errors translatable.

This now errors for:
anchors.undefinedAnchor: foo
x.undefinedAnchor

The idea is that it may be a plugin-provided type. We don't want user
code to be riddled with error markers in that case.

Reviewed-by: Roberto Raggi

Reviewed-by: Roberto Raggi

* 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.

Done-with: ckamm

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

Done-with: ckamm

Done-with: Roberto

Done with ckamm