gre.PLUGIN_ROOT
This is a variable that is filled in by the Storyboard Engine to contain
the path to the Storyboard Engine's plugins directory. This is the directory
that is specified to the model_mgr using the -omodel_mgr,plugin_path
option
or via the SB_PLUGINS
environment variable. This path can be used to load
application specific binaries that may be packaged with a particular Storyboard Engine.
This variable is only applicable for systems that dynamically load plugins from a filesystem.