video_query data is deleted when a new preview is loaded. This ensures
old query information doesn't persist on failed load.
Call onRemove on removed output format widgets. This doesn't matter for
any existing formats, but swapping to app.widgets allows for arbitrary
widgets to be included in formats which may require it.
Remove the app argument from the VHSFLOAT and VHSINT widget
constructors. These constructors aren't actually used, but this change
brings there functionality closer in line with the upstream sentiment.
Austin Mroz
2c25b8b538