start adding dynamic parameters into ffmpegwriter #70
put video preset in a group #70
only add video parameters #70
get parameters in FFMpeg writer
adding missing parameters
changing method to get help for each parameter
set closed groups by default
issue #70
Merge branch 'develop' into dev_cmdlineColors
Merge branch 'develop' into dev_colorGradationValidation
Merge branch 'develop' of github.com:tuttleofx/TuttleOFX into develop
Merge branch 'develop' of github.com:tuttleofx/TuttleOFX into develop
Merge branch 'develop' of github.com:tuttleofx/TuttleOFX into develop
Merge branch 'develop' of github.com:tuttleofx/TuttleOFX into develop
start adding all parameters dynamically for FFmpegWriter
Merge branch 'develop' into dev_ffmpeg_options

Conflicts:
	plugins/image/io/FFMpeg/src/ffmpeg/VideoFFmpegWriter.cpp
	plugins/image/io/FFMpeg/src/ffmpeg/VideoFFmpegWriter.hpp
	plugins/image/io/FFMpeg/src/writer/FFMpegWriterPlugin.cpp
	plugins/image/io/FFMpeg/src/writer/FFMpegWriterPlugin.hpp
	plugins/image/io/FFMpeg/src/writer/FFMpegWriterPluginFactory.cpp
Merge branch 'develop' of github.com:tuttleofx/TuttleOFX into develop
Set default bitdepth value to float when exporting EXR in OIIO plugin #138
FFMpeg adding dynamic options
adding video and audio parameters:
- boolean
- choice (with default value)
- string
- int, double, float
- rational
- image size
issue #70
adding specific parameters for all codecs and formats
issue #70
Merge branch 'develop' of github.com:tuttleofx/TuttleOFX into develop
Merge branch 'develop' into dev_clampingCorrections
OIIOWriter : define auto bitdepth according to file extension #138
Replace a number by its proper enum value in a default value setting