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
Add set-region/unset-region options to oo-admin-ctl-distict to allow set/unset of region/zone after node addition to district
Reuse loaded districts instead of querying mongo again to find Server object
Reorganize broker rake tests

Reorder tests in Rake test suite
Added test case for set/unset region
Fix broken tests
Rename 'server_identities' to 'servers' and 'active_server_identities_size' to 'active_servers_size' in district model
Rake tests: use glob to find remaining bunch for functional/functional_ext tests
Add ZONES_MIN_PER_GEAR_GROUP config param and related changes