Done-with: Roberto Raggi

Do not include the old description - this looks strange in some cases

Do not delete QmlPropertyMap items - they should be reused

Handling of QAction and global position

Enables completion for function declarations inside qml files.

Done-with: ckamm

Add the snippets to the completion box when the character at the left of the text cursor is a delimiter.

Done-with: Christian Kamm

Store the error message in the QTextCharFormat of the extra selection.

Activate the global completion when the the character at the left of the text cursor is a delimiter.

Move code to Foldernavigationwidget as static utilities and use
them from there and from the Project explorer. Fix error message box.
Task-number: QTCREATORBUG-62

The Navigator "called back" to the model in case e.g. the id
of an item changed. This was catched by the WriteLogger, which
lead to an assert.

Fix this by tracking whether we are changing the navigator items
due to a model change, and not reacting to itemChanged signal
in this case.