minimal script interface
TODO use JSR 223 or whatever the thing is and ditch custom code...
actions execute in a context of objects available at that time in that environment.
a context is a set of objects in certain roles, like the current_movie or current_player etc.
Contexts are a central concept in programming.
This class may go away and be replaced with the jdk1.6 scriptables.
it's used to run activities and scripts $
You can define functions, which are evaluated every time