GUI: handle aborted request (can't contact server)

- When request to server is aborted by browser (can't contact server), then
 status code of response is 0. Request must be handled in onResponseRecieved().

- Fixed display of connection lost widget in main GUI. Display it only
  when request is aborted by browser.
Merge pull request #565 from zlamalp/gui

GUI: handle aborted request (can't contact server)
UTILS: print also timestamp in pwdm log

- Also add help text for ldaps settings.
Change rules for getting rights for groupManager on attributes

 - change rules on member-resource attributes: only rights on any assigned
   group to resource are needed, add comment with definition of this rule
 - change rules on resource-group attributes: add comment with
   definition of this rule
 - change rules on user-facility attributes: groupManager need rights on
   any group (under resources of facility) which is from the same vo
   like some of users member, add comment with definition of this rule
 - change rules on user attributes: only has groupManager in vo where
   user has any member, add comment with definition of
   this rule
 - change rules on member attributes: only has groupManager in vo, where
   the member has membership, add comment with definition of this
   rule
 - change rules on vo attributes: change rights from NEVER to only
   has groupManager in vo, add comment with definition of this
 - do NOT change rules on group, resource, facility and host attributes
Merge pull request #566 from zlamalp/ldap

UTILS: print also timestamp in pwdm log
Merge pull request #562 from stavamichal/attributesRightsForGroupAdmin

Change rules for getting rights for groupManager on attributes
Fix and add some minor changes to XML extSource

 - xml extSource can send html header if it is set in configuration
 - fix closing of SSL connection
Merge pull request #567 from stavamichal/fixAndAddSomeMinorsToXMLExtSource

Fix and add some minor changes to XML extSource
New authz for topGroupCreator

TopGroupCreator can call getCompleteRichMembers and getGroups

GroupManager can call this methods anyway and topGroupCreator can easily
create group and become groupManager

This is hack for eduGAIN group service - because miniapplication for
eduGAIN group service call this methods at start and not when they are
really needed.
Do not set role VO_OBSERVER in eduGain registrar module

Users in eduGain group service should not see other user's groups
Hack to add perunv3/admin@META as privileged user
All VO edugain_group members get groupManager of members group

Without that they can't see other members' preferred mails.
AuthzResolverBl.getPerunPrincipal calls refresh authz

It's important for external application / libraries to have up-to-date
authz for actor.