Skeletal oauth plugin

Small enhancement to core allowing route description to explicitly
be set to None to disable the warning. Documented this functionality.
Implement frontend for oauth plugin

Also added our favicon to our swagger page
Add config page for oauth login plugin

Also add ability to set multiple system settings at once via the API
Use chainable idiom for girder event calls
Also allow settings to be retrieved as a list
Finish front-end for oauth admin configuration page
fixes #252 When receiving a 401 from rest requests, prompt for login

Then refresh the current route after login or logout succeeds.
Special handler for 403 that shows access denied message.
Fix failing style test
Merge remote-tracking branch 'origin/master' into oauth-plugin
Ensure highlighting of nav links stays consistent
Close the loop for google oauth login
Use a sensible default login when creating oauth users
Add some basic testing for the oauth plugin
Complete testing of google oauth workflow
Fix hardcoded redirect URL; redirect to current page on oauth completion
refs #164. Write docs about assetstores, including S3 assetstores.

- Reorganized some API docs that were out of place
- Fixed TOC bug
- User guide docs about Files
- Added first-steps guide in installation instructions
Add docs about plugins, and about oauth login plugin specifically
Put correct client Id creation values directly onto plugin config page
Merge pull request #250 from girder/oauth-plugin

OAuth login plugin