TextEditor: De-noise IAssistProcessor derived classes

...by providing a default implementation of immediateProposal() in the
base class.

Change-Id: I4f4f9aa491fbfc9390cc7b7093f1b3c1c8e460a4
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>
Tests: Move TestDataDir into plugintestutils.{h,cpp}

Change-Id: I76d5e421258eda85907e56762a59894ce7f84f13
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>
CppEditor: Remove CPPEditorWidget::modelManager()

...since it has no callers from outside.

Change-Id: I6e0432f957737254fa2c9154474bd16afdf7b324
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>
CppTools: Show function args in current document filter

Regression introduced by commit 190fb44.

Change-Id: Ibd47b6d316e5ae976fb448aad5062eb5887f10e6
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>
CppTools: De-duplicate some code in cppmodelmanager_test.cpp

Change-Id: I371e986c9b41fec5cddf05e3f7849c5e0b9e6b69
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>