Update the user manager commands.
cmd/jujud: ensure we don't ensureMongoServer twice

The upgrade-steps and StateWorker both call ensureMongoServer,
which is meant to check/set a flag so that we only set it up
once. There's an early exit case which meant that the flag was
not being set, which led to the upgrade-steps code restarting
mongo half-way through.

Fixes https://bugs.launchpad.net/juju-core/+bug/1338511
Merge pull request #279 from axw/lp1338511-machineagent-ensuremongoserver-already

cmd/jujud: ensure we don't ensureMongoServer twice

The upgrade-steps and StateWorker both call ensureMongoServer,
which is meant to check/set a flag so that we only set it up
once. There's an early exit case which meant that the flag was
not being set, which led to the upgrade-steps code restarting
mongo half-way through.

Fixes https://bugs.launchpad.net/juju-core/+bug/1338511
Added tests for IPv6 to peer grouper tests.
Merge branch 'master' of https://github.com/juju/juju into peergrouper-ipv6-testing
Don't kill instances if there are errors talking to mongo
Fix some error typos
Merge pull request #282 from wallyworld/provisioner-destroys-instances-incorrectly

Don't kill instances if there are errors talking to mongo

The provisioner was killing all deployed instances if it could not talk to the mongo database. 
This fixes that.
Update doc comments.
Merge pull request #277 from howbazaar/env-cmd-user-mgr

Remove EnvName from user manager juju commands

In further work to hide the environ command EnvName, the branch updates the various user manager commands.
state/apiserver: apiInfo.EnvironTag is now a Tag
test fixups
Merge pull request #284 from davecheney/133-names-refactor-part-vi

ApiInfo.EnvironTag now takes a names.Tag
Merge branch 'master' of https://github.com/juju/juju into peergrouper-ipv6-testing
Some simplification after review.
One final missed change.
Merge pull request #281 from TheMue/peergrouper-ipv6-testing

Added testing for IPv6 to peer grouper tests

So far the peer grouper only tests IPv4. As part of the IPv6 enabling the peer grouper testing now runs all tests for IPv6 too.
Rename config StateInfo() to MongoInfo() to better reflect the purpose of the method
Rename some more stateinfo attrs
Merge pull request #288 from wallyworld/rename-agent-stateinfo

Rename config StateInfo() to MongoInfo()

Agent config's StateInfo() method returns information for how to connect to mongo. There's also State() defined on Environs which returns api connection info. To avoid confusion, prepare for further refactoring, and better reflect the purpose of the method, it was renamed to MongoInfo()