Added oo-admin-ctl-region script to manipulate regions/zones

Modified oo-admin-ctl-district to handle region/zone during node addition

Fix district test cases

Added man pages for oo-admin-ctl-region

Updated oo-admin-ctl-district man page with region/zone details

When region/zone enabled, prefer gears in a group instance to belong to different zones within the current region

Move serializable_hash_with_timestamp method to model_helper.rb

Added unit tests for region/zone/district/app-creation

Added region/zone config params

Added region/zone info to GearProperties and NodeProperties model

Restrict district/region creation when DISTRICTS_ENABLED/REGIONS_ENABLED config is unset

Gear move fixes when regions are enabled
Bug fixes: 1055382, 1055387, 1055433