refactoring the feedFrame/renderFrame/getTexture flow to make a more
clever use of memory and autorelease pools
started implementing CVFilter
(on the way of having CoreImage filters usable from javascript)
any subclass of CVCocoaLayer with a controller associated to it can now
be controlled through the filterpanel.
The filter panel for a specific layer can now be opened by
double-clicking on the layer name in the listview.
a bit of refactoring in CVFilterPanel/CVLayerView/CVLayerController
has been done to allow viewless layers to be created and eventually
controlled through a filterpanel