Clicking on the map will now show you the value

Clicking on the map will now show you the value under the cursor.
Uses AJAX to fetch value from a THREDDS WMS server.
Actual call to WMS server is done by django to allow cross-IP calls.

Only works with a THREDDS WMS server.
Made click to view value work with low longitudes

For longitudes under -180 degrees, climate analyser will now wrap
these values before making an ajax call.
Merge pull request #15 from Andrew-Dunn/legend

Added click to view value function for map
Added calculation to model.
Got calculation working with current code.
Fixed issue in computation form where remove buttons would disappear on validation error.
Updated computation scheduling code. IDs added, now submits after Computation created, and result links (wms, nc, opendap) are fields in a Computation. Still needs to be tested
class for status response codes
merge
Fixing layout for computatons table
Merge branch 'master' of github.com:climate-analyser-team/bom-frontend

Conflicts:
	climateanalyser/templates/computations.html
Computation status now stored as object,  and also retrieved from resulting zoo xml file. Scheduling the computation in zoo is also now done automatically after each computation is created
Updated ajax code to update status - now takes status code
Added check for number of datafiles in form.
Moved check for number of datafiles in form to view.
Merge branch 'master' into climateanalyser
Moved check for data files back to form, but this time use self.data instead of request object so the code is can be used by admin backend. This is the correct and awesome way of doing it, woohoo!
Updated ComputationForm javascript so that when adding a new data
file, the URL will default to '----'.
Added variables to computation schedule request
Working on check to see if existing result already exists. Rough
and still untested. Need to also filter for calculation!