[#313] Error message for missing api version recommends version 3 instead of 1
[#313] Link to version 3 of the API on search results page
[#313] Routing defaults to the latest version of the API
Revert "[#313] Routing defaults to the latest version of the API"

This reverts commit 77d1c1be8a68b07ef2f5e152bdbf9f5185c35a50.
[#313] API routing defaults to the latest version of the API instead of version 1
[#313] Remove tests for unversioned API
[#313] Old APIs default to 1, the action API and the empty endpoint to the latest version
[#387] Always redirect to the url for the package controller
This is because package_type should not influence the page that is redirected to. The previous implementation had the problem that package_type is `package` by default which broke the redirection after editing the slug of a dataset.
[#387] `_get_package_type` returns `dataset` by default, properly handle redirect based on package type
[#387] Make pull request minimal by re-adding a new line
[#420] Clean imports for some controllers
[#420] Clean tag controller
[#437] Clean up some imports
[#450] Datastore field names cannot be empty
Merge pull request #437 from okfn/437-lib-search-imports

lib.search.__init__ messy imports
[#450] Refactored _is_valid_field_name
[#450] Add unit tests for field and table name validation
[#450] Improve functional field name validation test
Merge pull request #420 from okfn/420-controller-import-clean

Controllers import clean
Merge pull request #450 from okfn/450-datastore-empty-field-names

Datastore breaks if there are empty field names