[api] Removed references to HttpBasicEngine from Authentication Engine and replaced it with AnonymousEngine. IN-6
[api] Adding in anonymous authentication engine. IN-6
[api] Replacing HttpBasicEngine with CredentialsEngine. IN-6
[api] Renamed HTTP Basic Engine tests to match credentials engine test. Removed unused tests. IN-6
[api] Added condition to see if an anonymous user has been set. If they have, set permissions and return true. IN-6
[api] Using join on a comma instead of inspect. IN-6
[api] In case HTTP_USER_AGENT doesn't match obs-webui or obs-software send a better error message. IN-6
[api] Changed error message for when there is no authentication engine defined. IN-6
[api] When inspecting an authentication engine, make sure to call engine method on auth_engine object. IN-6