Added time of last submission getter
Added function to submit with editable transport instances
Return 404 if no records match query criteria
Also check deleted surveys when getting the last update time
Re-use existing export when data has not been updated
Updates csv and xls export to share a data export view and tests to use anmed url for csv_export and xls_export
Temporarily set test test runner to default django runner to make sure nothing is broken by export changes
Merge branch 'master' into return_newest_export_if_data_not_changed
Used old test runner just to be sure
Dont persist filtered exports to db
typo in comment
Merge branch 'master' into return_newest_export_if_data_not_changed
Merge with master and resolved conflicts
Merge branch 'master' into return_newest_export_if_data_not_changed

* master:
  Implemented language changes on column picker - fixes #955
  Updated query mongo to enclose query params in an  - fixes #622
  Dont explicitly convert to unicode
  Fixture for unicode characters in relevant column test
  Pass error as as and dont try to convert to unicode, it is propely rendered
  Added function to check if the message is unicode before trying to convert
  Explictly use message attribute of validation errors and encode to utf-8 incase message contains non-ascii characters
Merge pull request #1016 from modilabs/return_newest_export_if_data_not_changed

Return newest export if data not changed