To Do
  -  Streamline the process of generating tables. Show one
  trajectory at a time.
  
 -  Hide unused fields in the method editor.
  
 -  Collect and analyze test problems.
  
 -  Add copy and paste to the species, reaction and parameter lists.
  Also add ability to clear selected columns.
  
 -  Plot reaction propensities.
  
 -  Check export of compartments to SBML.
  
 -  Add import/export capabilities for SBML shorthand.
  
 -  The MS Windows backend for wxPython does not correctly fade
  disabled bitmap buttons. I have added explicit SetBitmapDisabled()
  calls to work around this issue. Remove these calls when this issue
  is resolved.