update openfx
Prepare code for more image components
Use proper warnings
BUGS: more bugs
fix test
BUGS: two more bugs
bug fix: use kOfxParamPropAnimates instead of kNatronParamFilePathIsImageSequence, which is redundant
OfxParamInstance: partially support kOfxParamPropIsAnimating

@MrKepzie : is the solution OK? This property should also be set on
File_Knob’s which have a sequence, but how can it be done?
2 bugs
The copy/paste/link knobs actions are now in a menu triggered by a
right click on the knob.
InitializeKnobs is now using setDefaultValue for all knobs.
Ofx params now can have their default value restored via the GUI.
OfxParamInstance: always set kOfxParamPropIsAnimating
Merge branch 'workshop' of https://github.com/MrKepzie/Natron into workshop
Added a restore default values button for all nodes
The File_Knob API is now the same as String_Knob and is now considered
as an animating param.
Next step is to have them interchangeable with the linking API
ComboBox: fix warning
OfxImageEffectInstance::newParam(): always set properties (when possible…)
BUGS: more bugs
BUG: another one