Add refresh authz to createGroup methods
Merge pull request #367 from stavamichal/groupManagerHasRightsToSubGroups

Add refresh authz to createGroup methods
Unpermitted logins check in module U:D:login_namespace
Merge pull request #368 from Simcsa/login

Unpermitted logins check in module U:D:login_namespace
New getMessagesByCount

- faster version
- there is no guarantee of message count returning
Merge pull request #370 from stavamichal/newGetMessagesMethodByCount

New getMessagesByCount
Substitute command "foreach" with "for"

foreach is available from Java 8, but Perun currently using only Java 7