Class GraphTable

__init__ instantiates the GraphTable object, given the graph
table name as an input string.

Input:  string GFile containing graph table name
Effect: populates four data members:
        keywords: CharArray of keyword names
        innodes:  Int32 array of innodes
        outnodes: Int32 array of outnodes
        compnames:CharArray of components names

Overrides: object.__init__

GetNextNode returns the outnode that matches an element from the modes list, starting at the given innode. This method isnt actually used, its just a helper method for debugging purposes

GetComponentsFromGT returns two lists of component names corresponding to those obtained by waling down the graph table starting at innode. The first list contains the optical components, the second list, the thermal components.