Updated Elasticache to support Redis & replication.
Fix glacier layer2.list_vaults and related tests.
support other ELB policies

Also add missing files from ec2/elb to the doc index.
Merge remote-tracking branch 'egirshov/elb' into develop
Merge remote-tracking branch 'kmwang/fix-glacier-list-vaults' into develop
Added docs about the included CLI tools & recommended people check out the AWS-CLI.
Merge branch 'elasticache-redis' into develop
Added notes for the release.
Bumping version to 2.12.0
Merge branch 'release-2.12.0' into develop

* release-2.12.0:
  Bumping version to 2.12.0
Added dev release notes back in, as well as a template for future laziness.