added jquery ui's autocomplete module to the frontend for autocompletion of system names during node creation
relevant css and images necessary for the module have been included
added a backend api to retrieve completion results of system names
changed the systemnode model to have a relationship with the system model since a db of all systems is now stored
name and type were removed from the systemnode model. as such, the tests, form, and js have been updated
a south schemamigration has been added with this change