add yosemite to macOSXSeries
Prevent destroy-environment when desired.
First cut ListNetworks
Fixed error construction and format. Renamed vars for clarity and conformity.
Cleaned up error-related code based on review.
worker/uniter/context/jujuc: symlink tools to correct destination

Hook tools were being symlinked to the unit-specific tools symlink
when the first unit was deployed. This causes problems when that
unit is destroyed, and another unit of the same service remains;
the symlinks remain broken.

We change EnsureSymlinks to dereference the target destination if
it is a symlink.

Fixes https://bugs.launchpad.net/juju-core/+bug/1391645
Made code readable
move filter implementation to its own package, put it behind an interface
use real NewFilter func in tests
Merge branch 'master' into listnetworks-maas
Merge branch 'master' into uniter-extract-filter
Merge branch 'master' into listnetworks-maas
Skeleton test for ListNetworks
Updated comment and logging
Add comments to test
SetFile -> SetFileInfo.
Update utils dep.
Merge pull request #1119 from ericsnowcurrently/backups-SetFileInfo

SetFile -> SetFileInfo

http://reviews.vapour.ws/r/415/
State: cleanup code

Remove useless code. change.C is the collection name, which is used to get the collection, which intern is used to set change.C to the collection name.
Ensure metadata file gets closed