aws, ec2, s3: Imported packages.
exp/{mturk,sdb,sns}: Imported packages.
s3: add Bucket.URL method
s3test: resurrect old bucket list code
s3: working server test on buckets
s3: steps towards getting bucket list tests working live. refactor tests to be more similar to ec2
s3: add Bucket.URL method

No pre-signed URLs yet though.

R=
CC=
https://codereview.appspot.com/6159044
merge trunk.
make bucket list tests work live.
go fmt
s3: use correct error message on GET not found.
s3: add new List test case
s3: minor changes for review
s3test: add list bucket functionality.

also refactor tests to match ec2 structure
and gofmt on the source tree.

R=niemeyer
CC=
https://codereview.appspot.com/6201062
s3: add support for dreamhost and bucket names in the domain

S3 supports two ways to address bucket names: via a common
domain name plus a path, and via a domain named after the
user bucket. This adds support to the latter convention.

It also includes support for talking to DreamHost's S3-like
endpoint, and fixes a bug in the tests.
Changes per Rog review.
s3: add support for dreamhost and bucket names in the domain

S3 supports two ways to address bucket names: via a common
domain name plus a path, and via a domain named after the
user bucket. This adds support to the latter convention.

It also includes support for talking to DreamHost's S3-like
endpoint, and fixes a bug in the tests.

R=rog
CC=
https://codereview.appspot.com/6211070
Refactored, preparing for signatures.
Implemented SignedURL.
Added .lbox
Applying review by Rog.