CppEditor/CppTools: Introduce Test{Case,Document}

Move common functionality of the 12 test classes into base classes.

Change-Id: If64d3cec876807ac6f991151189860a99b8ff4ca
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>
CppEditor/CppTools: Clean up *Test* classes

* Unify class names
* Fix coding style

Change-Id: I7498192ba9e6b9fc0e97d3d4f0dbb30f1853a0c9
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>
CppEditor/CppTools: Don't continue in test function on failure

QVERIFY/QCOMPARE are meant to be called in the test function so that on
failure they just can "return" and thus skip subsequent code. Since we
use reusable test code in the test functions (the *TestCase classes), we
need to ensure that on failure no further test code is executed.

This mostly inlines the run function of the test classes into the
constructor.

Change-Id: I320ee032bdde0174ddfe3fdf3f9e18e19abf1d7f
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>
CppEditor/CppTools: Avoid triggering garbage collector on editor close in tests

Closing an editor might trigger a timer which leads to the invocation of
the garbage collector. This is unfavourable for the plugin tests since a
test function closing an editor might influence a subsequent test
function (e.g. files get removed from the global snapshot although they
were added shortly before).

Change-Id: Ia80c11f99e2437fe145dc2d983b21962539b5181
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>