Initial work on depth of effect setting for Chase
Finish depth of effect for Chase and Spin effects

This should resolve issue VIX-125 (Depth Setting for effects), barring
any additional feedback
Added button to create a grid of timed marks

Note - in addition to the marks, I've added a tool tip to this and put
text in for all the buttons which give tool tips to help understand what
the buttons are for.
Allow depth of effect to be arbitrarily deep
Added RGB quick pick buttons to the color picker
Merge remote-tracking branch 'remotes/alphageek/Add-grid'
TimedSequenceEditor: minor fixups in the mark manager (typos, namespaces, etc.)
Merge work by akonkman: depth setting for effects