Fixed logging prefixes after moving state/api -> api/ and state/apiserver -> apiserver/
Merge pull request #659 from dimitern/fix-logging-after-api-move

Fixed logging prefixes after moving state/api -> api/ and state/apiserver -> apiserver/

After https://github.com/juju/juju/pull/655 got merged, I noticed some loggers are still using "state.api.*" and "state.apiserver.*", so this fixes these to drop the "state." prefix.

Also, added more logging to juju/testing/conn.go and state.Close() hoping to provide more context for fixing CI bugs like http://pad.lv/1348477.
Revert to using curl to download tools

aria2 is in universe, which would preclude
juju from entering main. aria2 is also not
available on the test machines, and broke
CI. Revert to using curl, but cycle through
the URLs until one succeeds.

Fixes https://bugs.launchpad.net/juju-core/+bug/1364438
Merge pull request #661 from axw/lp1364438-curl-download-tools

Revert to using curl to download tools

aria2 is in universe, which would preclude
juju from entering main. aria2 is also not
available on the test machines, and broke
CI. Revert to using curl, but cycle through
the URLs until one succeeds.

Fixes https://bugs.launchpad.net/juju-core/+bug/1364438
state: infrastructure for synchronising state server upgrades

Introduce a new UpgradeInfo struct (and underlying mongo document)
which will be used by state servers to synchronise tools upgrades.

Later commits will integrate this infrastructure with the upgrade
machinery in jujud.

William Reade and Menno Smits both contributed to this revision.