Add new searcher for searching Members by user attributes

- add method which use existing userSearcher, but returning members by
  specified vo
- add tests for new method
- fix some bugs in existing tests in Searcher
- add privileges test for new method
- add privileges test for all userSearcher methods (Entry)
- fix javascript
- remove some useless code
Merge pull request #413 from stavamichal/attributeSearcherForMembersUsingUserAttributes

Add new searcher for searching Members by user attributes