did ALL THE THINGS; uniter_test passing again; loads of cleanup to do
better reboot-error handling/layering in RunCommands
operations now return State, not StateChange, which has become an internal detail; moved responsibility for hook-completion state changes to the runHook operation. also make StateFile.Write accept a *State instead of a mindless blech of individual params
move interfaces into interface.go; tweak error messages
gaah add files
consolidate a bunch of disparate junk into operation.Callbacks
merge master
move setupLocks back, to make diff look smaller
Move charm archive logic to API server

The client no longer determines the charm archive URL
from the current API server address, but instead queries
the API server for a list of URLs to attempt. The uniter
will try each URL until one works.

Fixes https://bugs.launchpad.net/juju-core/+bug/1394976
fix ModeContinue, add failing (and some passing) tests
Block/unblock remove- commands and tests.
more callback tweaking; comprehensive(?) tests for runHook op
juju-run: adding relation-id and remote-unit support
juju-run: adding and updating tests
juju-run: added --no-remote-unit for explicit executions against relations with no remote unit
juju-run: ParseRemoteUnit fixes and tests
juju-run: adding additional conditions to the parseRemoteUnit test, review updates
jujuc: make relation flags match juju-run
juju-run: updates based on peer review
extended jujuc / juju-run support the same argument flags
renamed --no-remote-unit to --skip-remote-unit-check
changed --relation-id to --relation, added parsing of string inputs
added more testing
juju-run: add --relation to jujuc relation commands