Start storing trakt credentials in sync account.

- Unfinished.
Merge branch 'beta' into trakt-creds-account

Conflicts:
	SeriesGuide/src/main/java/com/battlelancer/seriesguide/ui/ShowsActivity.java
Manage trakt credentials with new TraktCredentials singleton.

- Also completely rewrite trakt connect fragment, it was a mess.
- Also rename the trakt service manager getters (now getTrakt and
getTraktWithAuth).
Migrate existing trakt passwords into account store.

- Also touch up upgrade code to use BuildConfig.VERSION_CODE constant.
- Push version to 204 for free, 216 for beta.
Remove encrypt from SimpleCrypto so no one gets the idea...
Remove credentials from trakt service before setting them invalid.
Correctly enable text fields after disconnecting from trakt.
Merge branch 'trakt-creds-account' into beta