Restored the notification app and adding some more notification types
Added support for i18n
fixes #1830
whitespace fixes
Fixes #1835
Merge pull request #1834 from state-hiu/fix_1830

Delete Comments,  Fixes 1830
Merge pull request #1836 from state-hiu/fix_1835

Hides Edit Layer, Fixes #1835
show categories if they have records
Merge branch 'master' of https://github.com/GeoNode/geonode
Merge pull request #1811 from capooti/restore-notification

Restored the notification app and adding some more notification types
Updated changelog for version 2.4b4
Update ec2.py