PLD: filter orgs out of user permissions lists, closes #557
PLD: add project serializer test
Merge pull request #558 from onaio/557-no-org-users-in-list

557 no org users in list
UK: submission serializer
UK: add xform submision api endpoint
UK: more permissions tests
UK: move TemplateXMLRenderer to onadata.libs.renderers
UK: submission urls to point to XFormSubmissionApi
UK: refactor _make_submission to call the submission function directly
UK: ensure we have a user profile
UK: authenticate subission with digest
UK: do not add xml submission as attachment
UK: allow head requests to XFormSubmissionApi.create
UK: update tests