Fix oauth errors to match the oauth spec

* Should return error and error_description properties
* Add OAuth2_Exception class to proxy errors from OAuth2_Response
* Update tests to expect 'error' not 'errors' property
* Check error message in tests
* Update submodule to fix some issues
Only return JSON errors for API
Forward Kohana Request headers to OAuth2 Request

Should fix issue authenticating internal requests.
Fix type on docblock comment: Relationhips -> Relationships
Better error handling when including gisconverter library
Merge commit '893cb2c'. Closes #55

Conflicts:
	application/tests/features/api.posts.feature
Test case fixes after merging posts changes
Revert to kohana/database url for database submodule now fix is merged
Merge branch 'oauth' into develop

Conflicts:
	.gitmodules
	application/classes/Controller/Api/Posts.php
	application/tests/features/api.forms.feature
	application/tests/features/api.posts.feature
	application/tests/features/forms/api.groups.feature
Fixes after oauth merge

* Fix "response status code" step changing to "guzzle status code"
* Add oauth2Skip
* Add required last_location values
* Add required form id to oauth posts requests
* Increase attribute ID in Updates fixture - avoid clash with existing
  attributes
Fix SQL error in Posts api when values array empty or not set

Need to pass at least 1 ID to NOT IN part of the SQL query.
Fix sets test cases after oauth merge