pgAdmin 4 commit: Make the privilege control to work as expected. Using

Make the privilege control to work as expected. Using the
NodeListByNameCell for selecting the grantee.

This patch includes:
- Change the RolePrivilegesModel schema to allow to use the
  NodeListByNameCell for showing grantee, and granter information.
- When setting some value - do not use the silent flag in Select2Cell, which
  will allow the session manager to take the value in account, which is
  used by the NodeListByNameCell.
- Set the top object in the children of the UniqueControl collections.
  [Ashesh Vashi]
- Pass on the node information to the actual data model, so that - we can use
  node information by the control itself. [Ashesh Vashi]
- While adding the new privilege, set the granter to the current user.
  [Ashesh Vashi]

Branch
------
master

Details
-------
http://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=4e5e7755b5705fd49b6a7f70bed216bde119450e
Author: Harshal Dhumal <harshal.dhumal@enterprisedb.com>

Modified Files
--------------
.../browser/server_groups/servers/__init__.py      |  3 +-
.../server_groups/servers/static/js/privilege.js   | 54 +++++++++++++++++-----
web/pgadmin/browser/templates/browser/js/node.js   |  7 ++-
web/pgadmin/static/js/backform.pgadmin.js          | 13 ++++--
web/pgadmin/static/js/backgrid/backgrid.pgadmin.js |  2 +-
5 files changed, 60 insertions(+), 19 deletions(-)