refactored token management and catching token revokation errors

[Ceesaxp]

Reworked token authentication, refresh and revocation handling. Instead of failing in getClient and getCalendarService use erro propagation to catch/retry or re-authenticate. Adjusted sync, add, cleanup, and desync to reflect the change.

[bobuk]

Please fix the the merge conflict and I'll merge it. thank you for what you are doing