Put SOS_BASE_DEFS_URL constant in settings.py. Pass it to the templates
and set the value in CONFIG.

Updated a couple of the tests to set this since they call
TimeSeriesVisualizationRegistry and were throwing a console error which
will cause phantomjs to barf. Removed GraphPopup.js because we have no
tests for it and it was also causing a console.log error.
Merge pull request #290 from mbucknell/NAWQAAN-377

Put SOS_BASE_DEFS_URL constant in settings.py. Pass it to the templates