Preserve blob metadata for AWS-S3 MPU

Specifically preserve content-type and content-disposition for
multi-part uploads.

Fixes JCLOUDS-204
Fixes multi-block upload for azure.

Currently files are not properly uploaded if they are a multiple of MAX_BLOCK_SIZE.
See https://issues.apache.org/jira/browse/JCLOUDS-233
Merge remote-tracking branch 'jclouds/master'
Add ByteSource Payload support for Clojure
JCLOUDS-410: Remove StreamingPayload

Only two tests use this class.  Callers should use ByteSourcePayload
or InputStreamPayload instead.
Address error-prone warning
Remove WriteTo

Guava helpers capture this functionality in a more idiomatic way.
Merge branch 'master' of github.com:maginatics/jclouds
Update README.md
Better documentation and a bugfix for cloud-init
JCLOUDS-342: Retry on HTTP 408 for swift

To repro issue 342, the following steps were taken:
 - Spawn 500 parallel / 2000 total putBlobs to cloudfiles-uk
 - issue a SIGSTOP
 - wait 60 seconds
 - issue a SIGCONT

Without this patch, there are several hundred 408s.
With this patch, these are retried and complete successfully.
JCLOUDS-460: Add jitter to avoid thundering herd

When issuing many simultaneous requests to Synaptic Atmos I observed:

HTTP/1.1 failed with code 500, error: AtmosError
[code=1040, message=The server is busy. Please try again.]

Previously all clients slept for fixed intervals and thus retried
around the same time.  This commit adds a random delay which should
better distribute load on the provider.
Address Checkstyle violation
JCLOUDS-486 This will allow booting up nova servers with fixed IPs and ports.
Fixing a couple of typos
Updating the features section to match the website
Address Checkstyle violations
JCLOUDS-453. Add OpenStack Keystone v2.0 OS-KSADM Admin Extension support for Keystone.
Merge branch 'master' of git://github.com/jclouds/jclouds