Migrate endpoints during upgrade.

broker code for endpoint upgrade of gears

Fix unit tests.
Keep proxy gears disabled appropriately

Modify enable-server to keep all proxy gears disabled if the ratio of
web to proxy gears is > 2 (previously this only applied to the
local-gear)
Bug 1003531: An warning message should be thrown out instead of error message when restore a app with postgresql-8.4 (and postgresl-9.2) cartridge
Merge pull request #4202 from bparees/psql_restore_invalid_error

Merged by openshift-bot
Merge pull request #4198 from ncdc/haproxy-keep-proxy-gears-disabled

Merged by openshift-bot
Merge pull request #4209 from mrunalp/dev/upgrade_endpoints

Merged by openshift-bot