state/multiwatcher: move remaining mutliwatcher related types
tests pass
remove unused types
remove vestigial type decl
Merge branch 'master' of https://github.com/juju/juju into 212-state-multiwatcher-info-types
responding to review feedback
Merge branch 'master' of https://github.com/juju/juju into 212-state-multiwatcher-info-types

Conflicts:
	apiserver/params/internal.go
gofmt
Merge pull request #1116 from davecheney/212-state-multiwatcher-info-types

state/multiwatcher: move remaining mutliwatcher related types

Followup to #1108 

It's pretty clear that these other types belong to the multiwatcher.
Improved svc.SetCharm and unit.SetCharmURL, added more tests
Merge pull request #1113 from dimitern/lp-1301996-settings-lost-after-upgrade-charm

Improved svc.SetCharm and unit.SetCharmURL, added more tests

This is an attempt to fix issues like http://pad.lv/1301996