[FEATURE] Table independent auth codes

It is now possible to generate auth codes that are independent from
a related database record.

Additionally some warnings are fixed and deprecated methods are
replaced.
[FEATURE] Update tstamp in record table

A new constant is introduced that enables the updating of the tstamp
field for the address records:
plugin.formhandler_subscription.updateDatabaseTimestamps

THe ValidateAuthCodeDB preprocessor now accepts a new config option
"updateTimestampOnRecordActivation". If this is TRUE the tstamp
field in the related record will be updated if configured in the TCA.

By default this constant is disabled to keep backwards compatibility.
[BUGFIX] Fix langFiles init in subscribe finisher

The addDefaultComponentConfig() method in the subscribe finisher is
not using the non existing $tihs->langFiles class variable any more
but reads the langFiles setting from its current settings array.