[#632] Modularize rest/views and rest/serializers

Create python modules for rest/views and rest/serializers and create
individual pfiles for each class.
[#632] Add Country resource

Add serializer and view set for Country.

Hook up CountryViewSet in urls
[#632] Add REST_FRAMEWORK setting

Add REST_FRAMEWORK to 30-rsr.conf and set pagination defaults.
[#632] Basic API setup of most of the remaining RSR models

Add serializers and view sets for most RSR models.
[#632] Cleanup

Remove unused imports

Add missing router registrations

Remove commented out fields
[#632] Add resurces for User and UserProfile
[#632] Cleanup

Remove unused imports

Alpha order imports
Merge pull request #641 from akvo/feature/632_rest_framework

[#632] rest framework