Add back spellchecking support

This reverts commit:
 * d364c05d
 * e507f140



Moreover it fixes shut down of keyed services,
updates versioning of and fixes spellcheck unit
test context menu request, which otherwise
fails on windows.

Change-Id: I9bfc589544cb969abd6d2d7af69531b4c5c907b7
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>