Implementing a basic hack for basic auth.

P.S.: The injection of public(!) static(!) members in Global.java
is terrible. Needs to be fixed.
Merge branch 'editableInputs' of github.com:Graylog2/graylog2-web-interface into editableInputs
Correcting the code to support passwords containing ':'.

Thank you, @alexquick
Adding API endpoints returning servers, radios and combined nodes.

Also changed usage of JSON serializer in json() helper to Jackson.
It is used right now in only a few places, but in general Jackson
is prefered over Gson and should replace it in the long run throughout
the code.