Update juju/testing dependency

Fixes LP #1325707.
utils: remove most of it and use juju/utils instead.

utils/ssh and utils/syslog remain in core pending removal of their
core dependencies.

This is a mechanical change.
add juju/utils dependency
Merge remote-tracking branch 'origin/master' into 002-move-utils
fix up imports after merge
fix accidental merge issue with pull request #16

https://github.com/juju/juju/pull/16
Merge pull request #32 from johnweldon/fix-mr-16

https://github.com/juju/juju/pull/16
here's your \t
merge from trunk
Merge pull request #10 from davecheney/101-update-juju-testing-dependency

Fixes LP #1325707.
Use github.com/juju/names package

Also remove unnecessary usage of errors package when fmt was already imported.
Fix test imports
Update dependencies.tsv
fix imports test
Merge branch 'master' of https://github.com/juju/juju into 102-remove-juju-names

Conflicts:
	provider/dummy/environs.go
	state/environ.go
	state/networkinterfaces.go
	state/networks.go
	state/relation.go
	state/relationunit.go
Merge pull request #34 from davecheney/102-remove-juju-names

Also remove unnecessary usage of errors package when fmt was already imported.
Merge remote-tracking branch 'origin/master' into 002-move-utils

Conflicts:
	dependencies.tsv
gofmt
fix dependency tests
Start using networks constraints for deployments:
- "juju deploy" uses --networks=net1,net2 argument to specify
  requested networks (required to be enabled), while "softer"
  requrements only for instance selection can be given with
  --constraints networks=net2,^net3 (positive and negative)
- updated help topics
- changed MachineConfig to only have Networks (to include)
- changed RequestedNetworks in state for machines and services
  to have only a list of included networks
- changes in the MAAS provider to use both requested networks
  and network constraints for acquireNode
- provisioner API and worker uses requested networks as
  from a single slice, and ProvisioningInfo-related code was
  updated similarly
- juju status changed to show only requested networks as enabled
  and networks from constraints as disabled for a service
- fixes in lots of places (mostly tests)

There are a lot of changed files, but most of them are just
fixed tests and code using NewMachineConfig or AddService,
whose arguments have changed.