support functions for Jython editor completions.
is the carot within a subclass of an identifiable Java class? TODO: this is a proof-of-concept kludge right now, where it just looks for g.*
get the completion context for the editor at the carot position.
Get the completion context, locating the carot within the code and identifying it as needing a package name, variable name, function, etc. This parses the line using PythonGrammar