Added code that posts data in the configure analysis view to the controller, along with some validation.
Added validation code to check the values that are returned during the POST.
Changed values returned from configure analysis page from dataset names to dataset ids.
Implemented the create method for the analysis object, along with a test.
Refactored some of the code in the analysis controller, and in the configure analysis form.
Merge branch 'master' of https://github.com/NERC-CEH/ecomaps

Conflicts:
	ecomaps/controllers/analysis.py