JCLOUDS-534: Upgrade to Guava 17.0

Release notes:

https://code.google.com/p/guava-libraries/wiki/Release17
JCLOUDS-505: Remove unused ObjectMD5

The only users of this seem to be
org.jclouds.atmos.blobstore.strategy.FindMD5InUserMetadata and
org.jclouds.azureblob.blobstore.strategy.FindMD5InBlobProperties which
are themselves unused.
Address Checkstyle violations
JCLOUDS-561: Properly populate the ssh agent connection in the builder methods
Enforce that all commas have trailing whitespace
Enable whitespace around Checkstyle rule
Updated ServiceType refs in Cloud Databases
Remove deprecation from getConsistencyModel

This method informs callers of the expected blobstore behavior,
avoiding unnecessary work for providers which support strict
consistency (Azure, mock blobstores).
JCLOUDS-563: Upgrade parent pom to version 14
JCLOUDS-564. Add ephemeral disks for m3.xlarge and m3.2xlarge sizes
Update pre-ASF copyright notices
Upgrade to maven-findbugs-plugin 2.5.3

Changelog:
http://jira.codehaus.org/secure/ReleaseNote.jspa?projectId=11701&version=17239
Upgrade to Checkstyle 2.12.1

Checkstyle 2.12 changelog:
http://jira.codehaus.org/secure/ReleaseNote.jspa?projectId=11127&version=19723

Checkstyle 2.12.1 changelog:
http://jira.codehaus.org/secure/ReleaseNote.jspa?projectId=11127&version=20236

Checkstyle 5.7 changelog:
http://checkstyle.sourceforge.net/releasenotes.html
Fix Accept header and removed Content-Type from common headers
Fixes an issue where the number of retries was always set to 1.
Prefer Guava HttpHeaders over JAX-RS

jclouds code contains more instances of the former and Guava has
additional constants like CONTENT_MD5.
Update openstack-keystone RetryOnRenew to handle 408 errors with a BackoffLimitedRetryHandler
Make constants final classes instead of interfaces

This commit prohibits implementation of the empty interface and
instantiation of the class.  Refer to _Effective Java_ item 19 for
more background.
Migrate InputSupplier callers to ByteSource

A future version of Guava will remove InputSupplier.
Replace InputSupplierMap with Map<K, ByteSource>

A future version of Guava will remove InputSupplier.