s3: Allow an arbitrary HTTP client to be used
Correct ASG tag types, names, and application

Ref http://docs.aws.amazon.com/AutoScaling/latest/APIReference/API_TagDescription.html.
More complete and correct LC and ASG handling

In particular:

* Add a few fields to structs to better reflect the complete AWS APIs.

* Adjust `member>` handling in XML tags to correctly parse multi-item
  elements (ref #97 for a similar case).
ec2: bump version to 2014-06-15
skip signing request if no auth secret is present
Merge pull request #111 from vito/s3-no-auth

skip signing request if no auth secret is present
autoscaling: Support passing the IAMInstanceProfile through to a launch configuration
implement http://goo.gl/DFySJY
Merge pull request #115 from burn-notice/DescribeInstanceStatus

implement http://goo.gl/DFySJY
Merge pull request #114 from grahamc/iam-instance-profile

autoscaling: Support passing the IAMInstanceProfile through to a launch configuration
elb: support Scheme on load balancer describe
elb: remove duplicate scheme
Don't include some params into signpath while preparing request.

These params would be added automatically by sign function from sign.go.
Merge pull request #116 from smira/master

Don't include some params into signpath while preparing request.
add option IamInstanceProfile to CreateLaunchConfiguration for allowing aws role base AC
a small code format change
ec2: use later API version
Merge pull request #117 from xuwang/master

Add option IamInstanceProfile to CreateLaunchConfiguration for supporting aws role base AC
ec2: add DeleteTags
Merge pull request #109 from mitchellh/bump-version

ec2: bump version to 2014-06-15