Provided better error for unit hosting on state server.
Stub EnvrionCapability.SupportsAddressAllocation methods
Rename method
Test stub methods
Typo fix
factor operation state out of uniter packager
make serialization explicit, update field names
more meaningful names for uniter fields; trivial consequent rearrangements for line length
put top-level test funcs in right place
fix imports, package names
silence stupid warning on push
second attempt at silencing stupid warning on push
Add joyent test
Fix uniter test for the periodic execution of the collect-metrics hook.
Merge pull request #920 from tasdomas/uniter-collect-metrics-test-fix

Fix uniter test for the periodic execution of the collect-metrics hook.
Provided better error for unit hosting on state server.
Bug 1378792
Default to using ssd storage for ec2 instances
Refactored common functionality to base struct based on review comments.
Bug 1378792
Optional Storage constraint no longer a pointer
Merge pull request #922 from wallyworld/aws-ssd-root-disk

Default to using ssd storage for ec2 instances

Fixes: https://bugs.launchpad.net/juju-core/+bug/1381009

When an EC2 image is searched for in simplestreams, the preference is to use one with SSD storage. If none is found, an image with EBS storage is used if found.

Also cleans up the image filtering which was incorrectly hard coding the storage type to search for.