ProjectManagerView: Fix key-handling issue

Personally, I can't reproduce the bug. This patch should fix the
unwanted behavior for sure, though.

BUG: 330134
FIXED-IN: 1.6.1
Make performance test work properly.
Fix memleak, QWidget without parent not being deleted.

Signed off by Apol
TemplateClassGenerator: Do not multiply bases

Fixes example no. 2 from
https://bugs.kde.org/show_bug.cgi?id=330285#c0

CCBUG: 330285
TemplateClassGenerator: Fix signature on override

Some members of FunctionDescription were not forwarded to Grantlee,
fixing this.

BUG: 330285
cmake: use the qjson include dir
Merge remote-tracking branch 'origin/1.6'
assistant popup: avoid expensive position recalculations when not required

This should fix high CPU usage or even lag during scrolling.
CCMAIL:kevin@kfunk.org