To make it work with the HistoryCompleter.

this has only an effect if parsing the previous file failed in a place
with a non-empty stack.

testing data, children and resources properties

This allows more precise unit tests on internals

Task-number: QTCREATORBUG-2339

Inform the user about projects that failed to load as part
of a session.

Reviewed-by: dt

Do not throw projects that failed to load out of the session.
Remember the project file names and append them to the session
again when saving.

Reviewed-by: dt

Only kde-config (and the defined paths) was being considered previously.

Sometimes the role is not enough. In some systems we don't have a nice looking widget.
The info bar is now always black on light yellow. The fake vim command status is using default colors.

Task-number: QTCREATORBUG-2182
Reviewed-by: Thorbjorn Lindeijer

Task-number: QTCREATORBUG-2307
Reviewed-by: Thorbjorn Lindeijer

Reviewed-by: hjk