oo-diagnostics: test_node_containerization_plugin

Add the test_node_containerization_plugin test to ensure that
OPENSHIFT_NODE_PLUGINS in /etc/openshift/node.conf does not include
unix_user_observer.
Remove references to deprecated MONGO_REPLICA_SETS

Remove references in the default broker.conf and documentation to the
MONGO_REPLICA_SETS setting, which was removed in commit
2449f2e62b47f8a7e1e69ea0c1db7419b82a167e and commit
4346b2c98717cd7f264973e1c2e2e206abef471c.  These references were
erroneously added in commit e4f862733adf9a5ed75dc3065a584a83de1797b8.
Bug 99445 - Better error message for No nodes available

https://bugzilla.redhat.com/show_bug.cgi?id=994445

Fix the error message to the user when NodeUnavailableException
is raised.
HAProxy fixes.
<Admin::Stats> fix minor bug - NONE district should be HashWithReaders
<Admin::Stats> exclude inactive nodes from eff avail gears

district_summary[:effective_available_gears] should be the number of
gears that are really available for creating new active gears in a
district. So, it now excludes nodes marked inactive in the district.
NONE districts are excluded from this logic since they don't really
have active/inactive nodes.
<Admin::Stats> use only strings for hash keys

This also enables using JSON for serialization - previously it didn't
record the difference between symbols and strings; now there are only
strings, so we can read JSON in usefully with oo-stats.
Writing env ERB files in the wrong location.
fix old mirror url

fix cartridge old mirror url
The upstream-repo is no longer necessary.
Merge pull request #3413 from sosiouxme/admin-stats-fixes

Merged by openshift-bot
Bug 994419
Merge pull request #3411 from mrunalp/bugs/haproxy_fixes

Merged by openshift-bot
Merge pull request #3398 from detiber/bz994445

Merged by openshift-bot
Merge pull request #3416 from rmillner/BZ998444

Merged by openshift-bot
Merge pull request #3417 from abhgupta/abhgupta-scheduler

Merged by openshift-bot
Bug 998683 - oo-accept-node failed to read manifests from source
removing v2 specific logic
Bug 998444 - Jenkins fixes.
Bug 997352 - Added usage_record -> usage inconsistency checks