Add GetGlueSettings to store OAuth 2.0 tokens.
Built in new GetGlue authentication and token retrieval.
Move GetGlue checkin to getglue-java. Still incomplete.

- Remove unused code, remove signpost lib, move credentials clearer to
GetGlueSettings.
- Rename GetGlue to GetGlueCheckin.
Clean up.
Move check-ins to new GetGlueCheckin and GetGlueSettings.

- For shows need to ask the user for a GetGlue id at first check-in, for
movies rely on the first search result.
Fix ref to GetGlueSettings in SeriesGuidePreferences.
Change callback url to seriesgui.de to avoid server error.
Use latest getglue-java snapshot, requires okhttp.

- Now integrates custom HTTP client to get access tokens.
Use getglue-java helper to get tokens.
Always ask user to define GetGlue object id if none exists, yet.
Crash if launching FixGetGlueCheckInActivity with invalid params.
Fix crash when no GetGlue id known in check in dialog.
Abort right away if GetGlue check-in fails.
Update to latest getglue-java snapshot, fixing interactions crash.
Use 1.1.0 release of getglue-java.
Use ABS supplied Window constant in fullscreen activity.
Perceive GetGlue access token as expired one day early.
Try to renew access token with refresh token when checking in.

- Unified code with GetGlueAuthActivity, only difference is the
submitted auth code. Once a refresh token, once a code returned when
first authenticating.
Do not ask for GetGlue id if there already is one.

- Add GetGlue id as required parameter to show check-ins.
Merge branch 'getglue-v3' into beta