Merge pull request #13 from pez4brian/master

Convert glow filters to QML
Update English translation with new/moved strings.
Fix typo in Highlights string for frei0r.coloradj_RGB UI.
Add Wave non-GPU video filter.
Fix possible crash adding filter.

We were permitting the addition of filters to the wrong producer, which
could have been something invalid such as the multitrack tractor when no
shot selected on the timeline but program monitor active.
Rename blur filters.