Clean up internationalization changes

 - Get rid of deprecation warning (and test we can handle new default for enforce_available_locales)
 - Move setting up of internationalization in to ApiError class so that it gets tested by api_error_spec
 - Ensure locale header is set in front_controller rather than base_controller so that requests that don't go via base_controller (such as 404s) also get i18n-ed error messages
 - Fix up some test pollution by reloading i18n backend in setup

[#74023440]

Signed-off-by: Michael Fraenkel <fraenkel@us.ibm.com>
Support special characters in staging_upload auth

 - To avoid breaking users who currently supply username/password already-encoded in the config file, only kicks in if the current value is not already validly encoded
 - This means it remains possible to simply specify url-encoded users and passwords in the config file, but if users do supply unencded values we'll attempt to do the encoding ourselves rather than blowing up

Fixes issue reported in #245

[#71526114]

Signed-off-by: Michael Fraenkel <fraenkel@us.ibm.com>
Remove dead SpacesController::ServiceSerialization module

[#67279870]

Signed-off-by: Michael Fraenkel <fraenkel@us.ibm.com>