Add tooltip for toggle pictures

Fixes #618

Signed-off-by: Miika Turkia <miika.turkia@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Typo fix Ave. => Avg.

Fixes #619

Signed-off-by: Miika Turkia <miika.turkia@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Change default export tab to "General export"

I prefer that we show the first tab by default. Everyone should remember
that Qt Creator changes the currently shown tab as default on save.

Signed-off-by: Miika Turkia <miika.turkia@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Remove theme directory when uninstalling on Windows

I assume the theme directory should be deleted on uninstall the same way
e.g. Documentation directory is deleted.

Signed-off-by: Miika Turkia <miika.turkia@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>