[#139] Remove /rsr from URLs paths.

When RSR runs on its own subdomain, the /rsr prefix in the paths is not
needed any more so remove it in urls.py and all places in templates etc
where it's hard coded.
Merge branch 'feature/rsr_subdomain' of github.com:akvo/akvo-rsr into feature/interim_home_page

Conflicts resolved in:
	akvo/templates/partner_sites/auth/sign-in.html
	akvo/urls/rsr.py
[#263] Changes to allow RSR to be deployed on a non-root app path.