added docs for PaymillContext
improved transaction response code interface.
API V2.1 added new web hook types for subscription
fixing handling of recursive objects
Improving interval, adding weekday
API v2.1 subscription create and part of update
API v2.1 subscription pause and unpause
API v2.1 changing of amount
API v2.1 subscriptions change offs, fixing some issues with parameters
API v2.1 subscription end trial
API v2.1 subscription limit and unlimit validity
API v2.1 subscription delete and cancel
API v2.1 removing offers
API v2.1 creating preauthorization now returns a preauthorization and not a transaction
Fixing test suite