TWC Patch 2014-08-28

Apologies for the large PR again. In the currents of change I haven't been able to get a process in place to do PRs per patch/feature. As of tomorrow that process should be in place though, so you should be seeing much smaller patches from us.

Changes:
- New operation to the MachineImageSupport: copyImage, which copies given image to another region.
- Main property to RoutingTable -- allows identification of main/default routetables over others.
- Support for attributes (crossDataCenter, timeout, etc) on load balancers.
- Add/remove listener support to load balancers.
- Ability to set firewalls when creating load balancer.
- Add health check info to LoadBalancer.
- Add volume info to machine image.
- Add set/list notificationConfigs to AutoScalingSupport.
- Added synchronous call to create tags.
- Deprecated subnetIds property (comma separated string) and added new String array for subnetIds in Scaling Groups.
The only use of this at this point is to disable keep-alive connections when calling the EC2 API - 
https://github.com/greese/dasein-cloud-aws/pull/187/files#diff-517e3c9d3f4d7e1bf2af21bed70afa66R652.

I added this because we've been experiencing failures in our tests because AWS caches properties and tags in between requests and a *launchInstance->addTag->verifyTag* test (and similar) were failing frequently. I can't find the link now, but I had come across a link that said disabling keep-alive connections to the API could help with this as it would force your subsequent request to go to a different AWS API server and perhaps miss the cache and get updated data.