CESNET/perun — pull request #603 by stavamichal (2014-12-03 10:33:09+00:00)
Title: Set LastSuccessSynchronization timetamp when synchronize groups

- new attribute group_def_lastSuccessSynchronizationTimestamp which is
set only when exception message is equal to "OK". OK means that no
exceptio was thrown in the middle of synchronization.
- if this attribute definition is not exists, only log this to
log.error

NEED TO BE DONE BEFORE MERGE:
- should create new attribute:
- String, group_def_lastSuccessSynchronizationTimestamp
- add information about new attribute to changelog