Coverity Scan and Krazy fixes

Fixed problems reported by Coverity Scan
Fixed problems or quiet false positives reported by Krazy

Change-Id: I22fd3e8276a5ab31e6b32ba92fcbfc81aebb8b47
Reviewed-on: https://codereview.kdab.com/12857
Reviewed-by: Continuous Integration <build@kdab.com>
Reviewed-by: Volker Krause <volker@kdab.com>
normalize signals and slots (using the Qt normalize tool)

Change-Id: I08948cd4a622c78e3c027e7306485ea9b8cd416f
Reviewed-on: https://codereview.kdab.com/12858
Reviewed-by: Continuous Integration <build@kdab.com>
Reviewed-by: Volker Krause <volker@kdab.com>