Merge topic '13788-FixSignalHandlers' into pv-master

4db9668 Merge remote-tracking branch 'origin/master' into HEAD
7ca2638 Disable python signal handlers in matplotlib module.
aaee29e Merge remote-tracking branch 'pvvtk/pv-master' into HEAD
Merge remote-tracking branch 'pvvtk/pv-master' into HEAD

* pvvtk/pv-master:

Change-Id: I943babf081d9ecef0fda6d208995c9ea70c1a371