Variometer API Additions

I cahnged the call from IRISFactory to FDSNFactory in data.py, updated the validator in DataAPIQuery.py to accept Variometer IDs, added a new file called variometers.py so that the ASL_Observatory_index can be used by the webservice, and this includes a change to app.py where I added a router to the new variometers.py script. I opted to not change any of the file names currently, but will give this some more thought. I wanted to commit these chagnes soon so that Nick can begin working on the front end.