* Add InvalidTokenException
* add DefaultTokenMapper and use it to check if a auth token exists
* create new token for the browser session if none exists
hash stored token; save user agent
* encrypt login password when creating the token
As discussed we move all old style classes (OC_FOO_BAR) to legacy.
Then from there we can evaluate the need to convert them back or if they
can be fully deprecated/deleted.
Lukas Reschke
Vincent Petry
Christoph Wurst
Roeland Jago Douma