Filter profiles for UI use

Note: This patch changes API behaviour.
get_cert_profile and get_possible_profiles_for_role now only return
such profiles that have an ui section. You can set NOHIDE to your call
to get all profiles (old behaviour)
Add epoch format to autodetext in OpenXPKI::DateTime::get_validity
Fix logging bug
Change Workflow::pause call parameters, fix logging and error handling

workflow->pause now requires epoch and not interval specification
calculation of epoch timestamp is now in Activity::pause.
Allows better support for setting explicit wakeup times
Add support for delayed revocation

Accept invalidity time in the future, uses the watchdog to pause the workflow
Remove unused Sleep activity
Support for certificate replace using scep

See SCEP docs for details, requires additional config to become active