various: gocheck, checkers, imports fixes

various: gocheck, checkers, imports fixes

This fixes several things across the codebase:
* gocheck is imported as gc in every file
* testing/checkers is imported as jc in every file
* imports are properly grouped as standard, 3rd party and juju-core

https://code.launchpad.net/~dimitern/juju-core/137-fix-state-imports/+merge/185519

Requires: https://code.launchpad.net/~dimitern/juju-core/136-params-error-code-helpers/+merge/185461

(do not edit description out of merge proposal)

[rog, 2013-09-13 15:06:54]

LGTM with one minor point.

https://codereview.appspot.com/13606045/diff/1/names/environ.go
File names/environ.go (left):

https://codereview.appspot.com/13606045/diff/1/names/environ.go#oldcode6
names/environ.go:6: import "strings"
I think this is still fine for a single import.

https://codereview.appspot.com/13606045/diff/1/names/user.go
File names/user.go (left):

https://codereview.appspot.com/13606045/diff/1/names/user.go#oldcode6
names/user.go:6: import "strings"
ditto

[dimitern, 2013-09-13 15:17:07]

https://codereview.appspot.com/13606045/diff/1/names/environ.go
File names/environ.go (left):

https://codereview.appspot.com/13606045/diff/1/names/environ.go#oldcode6
names/environ.go:6: import "strings"
On 2013/09/13 15:06:55, rog wrote:
> I think this is still fine for a single import.

As agreed online: it's about consistency, and only these 2 files in the whole
codebase import a single package inline, rather than in a block. There are
plenty of examples of single import blocks.

https://codereview.appspot.com/13606045/diff/1/names/user.go
File names/user.go (left):

https://codereview.appspot.com/13606045/diff/1/names/user.go#oldcode6
names/user.go:6: import "strings"
On 2013/09/13 15:06:55, rog wrote:
> ditto

Same answer as above.