When adding or removing groups on a user object, the merged permissions cache should be cleared.
Merge pull request #420 from CodeYellowBV/master

When adding or removing groups on a user object, the merged permissions cache should be cleared.
Check config for persist connection.
Merge pull request #474 from Min2liz/patch-2

Check config for persist connection.
Model + Interface + Test: new updateGroups function added for multiple add/remove user groups, tests added for single and multiple add/remove groups #477