Remove references to csv or upload format

This will be determined on upload, the user should be able to upload
either
Protect routes with a decorator

sorts out session availability in templates
with tests
remove irrelevant comment
Do signout and environment stuff

Also comments about things to still be done in upload story
Rename the manifest file

it breaks autocompilation if not, it's harder to make it output to a
different file name and there is enough context in it being in the
manifest directory
Fix tests - we need the fake get context to give and environment
Contact link to mailto for now
Merge pull request #19 from alphagov/template-fixes

Template fixes