Draw Glycan

Oliver got draw glycan working at the gmml level. Dan has the Draw Glycan interface ready to start writing submission logic.
Still need:
- graph gems module needs to receive and delegate to the process Oliver used.
- data structure to support the requests and responses
- javascript logic for request submission
- python logic for request submission
- python logic for response capture, validation, and return
- javascript logic for updating the page with response data.
- javascript logic for downloading the svg file.