Cleanup for new names.ActionTag refactor

hide implementation details more, rearrange code layout, simplify
Update the add machine api to accept both environment name and UUID.
Add a method to get the environment uuid from the client api connection.
Update dependencies.tsv
Use the environment uuid instead of the name.
Use the NewAPIClient method from the env command.
Merge pull request #248 from davecheney/128-update-ssh-terminal

Update dependencies.tsv

Fixes https://bugs.launchpad.net/bugs/1337063
Merge pull request #249 from howbazaar/env-cmd-add-machine

Update add machine to use environment UUID

This is the start of the work to hide the EnvName from the environment command base.

This will allow us to specify an environment using either other command line parameters or environment variables to better allow scripts to call juju without having a $(JUJU_HOME)/environments directory.
Renamed doc/planning to doc/contribution.
Changed to plural after review.
Merge pull request #252 from TheMue/rename-doc-planning-to-contribution

Renamed doc/planning to doc/contribution.

Simple renaming of the directory `/doc/planning` to `/doc/contribution`.
SetPreferIPv6Addresses implemented
Merge pull request #254 from dimitern/dummy-provider-ipv6

provider/dummy: Allow IPv6 addresses for instances and storage

Added SetPreferIPv6Addresses() method on the dummy provider
that controls whether to add IPv6 addresses to started
instances and what storage URLs to use (IPv4 or IPv6).
Also sets the network.PreferIPv6 flag, which influences
addresses selection to prefer IPv6 addresses when available.
Rename HydrateActionTag to JoinActionTag

update names dependencies
Merge branch 'master' into actiontag-refactor
Update Makefile with CI infrastructure changes

The CI scripts do a few hacks to our Makefile so it works better for them.
Bring in those changes, and also cut down the number of packages we install
by omitting build-essential and using the --no-install-recommends flag.
dependencies.tsv update for names package update
Ordered the lookup of machine IDs to guard against randomly ordered map key.
Merge pull request #258 from bz2/makefile_build_updates

Update Makefile with CI infrastructure changes

The CI scripts do a few hacks to our Makefile so it works better for them.
Bring in those changes, and also cut down the number of packages we install
by omitting build-essential and using the --no-install-recommends flag.
Merge pull request #259 from katco-/1329637-map-ordering

Ordered the lookup of machine IDs to guard against randomly ordered map ...

In Go v1.3, map ordering was intentionally randomized to discourage relying on maps which were coincidentally ordered how expected. This corrects a non-deterministic bug in one of the tests which was caused by this change to Go.