GUI: added support for groups as entities managers

 - TabMenu - proper way of styling and widget putting
 - added calls to get/add/remove managers groups
 - added new buttons translation
 - groups can be VO/Group/Facility managers
 - removed unnecessary code
 - groups to be added as managers are offered based on VO/Group admin rights
 - if 'members' group is about to be added, warning is show to inform
 user about consequences
Merge pull request #72 from zlamalp/admins

GUI: added support for groups as entities managers
Removed unused context filter from RPC.
CORE: fixed up javadoc

 - removed testing println from RTMessagesManager
 - updated javadoc in interfaces (fix is based on IntelliJ Idea's
 code inspections)
GUI: simplified password reset

 - do not allow to choose namespace after page loading
 - show login & namespace in page title
Merge pull request #75 from zlamalp/reset

GUI: simplified password reset
Merge pull request #73 from tauceti2/rpcRemoveUnusedFilter

Removed unused context filter from RPC.
Perun licence.
Merge pull request #74 from zlamalp/cleanup

CORE: fixed up javadoc
GUI: fixed application form

 - proper onPaste/onCut in password textboxes
 - on type checking for used login
 - fixed style of PasswordTextBox widget
 - fixed style of CheckBox widget
 - align app form row to top because of large widgets
Merge pull request #76 from zlamalp/input

GUI: fixed application form
CORE, RPC, GUI: allow to get assigned rich resources for user

 - added getAssignedRichResources for User to CORE, RPC & GUI
 - allow to set member-resource attributes on perun admin's user detail
Merge pull request #77 from zlamalp/resource

CORE, RPC, GUI: allow to get assigned rich resources for user
Core: New type of user attribute timezone.

User attribute timezone is now in standart of tz database, http://en.wikipedia.org/wiki/List_of_IANA_time_zones.
- the timezones in string are typed in the module and added to HashSet,
  since HashSet has constant time complexity of searching
- timzone attribute modul edited, so as it checks the value according to
  the timezones in set
- tests modified
Merge pull request #78 from jirmauritz/timezone

Core: New type of user attribute timezone.
Added user into Exception in module sshPublicAdminKey
Merge pull request #79 from papperwing/ssh

Added user into Exception in module sshPublicAdminKey
CORE: getRequiredAttributes for list of services

 - adedd getRequiredAttributes method for facility and list of services
   (implementatiton should be fixed in future to use single select to DB
   instead of calling method for each service)
 - added checkAttributeValue for Group to api layer to fix javadoc references
 - fixed many typos in AttributesManager javadoc
RPC: added getRequiredAttributes method to RPC

 - added getRequiredAttributes method for Facility and list of services
 - fixed up RPC javadoc
GUI: improved Create facility wizard

 - UI improvements to wizard pages
 - fixed empty result message for admins groups calls
 - support for getting required attributes for facility and list of services
 - when wizard closed, refresh facilities select table
 - added ExtendedSuggestBox and ExtendedTextArea widgets