Upgrade to Maven Checkstyle Plugin 2.13

This release fixes an issue we encountered with parallel builds:

https://jira.codehaus.org/browse/MCHECKSTYLE-230
https://jira.codehaus.org/browse/MCHECKSTYLE-244

Release notes:

http://www.mail-archive.com/announce@maven.apache.org/msg00611.html
JCLOUDS-692 Remove the CloudSigma v1 provider.
JCLOUDS-735 Remove ninefold providers.
Aligning indents in checkstyle config file
Excluding checkstyle.xml from Checkstyle checking

Since 5bac61d9 (update to Checkstyle 2.13), fails on itself
as it includes '@author' in a module definition.
JCLOUDS-538: Avoiding a VM crash trying to run live tests for Swift

TestNG was throwing up as its reflection was unable to find certain test methods
JCLOUDS-736: Revert "Fail build on checkstyle warnings"

This reverts commit 9384575d1ee4c2e68ff503b237dfedf8ab6b14bb.  This
caused errors of the form:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-checkstyle-plugin:2.12.1:check (checkstyle) on project jclouds-core: Failed during checkstyle execution: Unable to process configuration file at location: resources/checkstyle.xml: Cannot create file-based resource:invalid distance too far back -> [Help 1]

Likely due to running checkstyle during the validate phase which runs
before the package phase where checkstyle would find its resource jar.
JCLOUDS-150 add SubmissionAsyncBlobStore; unasync s3 and aws-s3
Revert "Revert "Revert "Unhook modernizer from verify phase"""

This reverts commit 2c790c897e91404704a3b29f37517ba60e776e66.  We
originally unhooked modernizer in a misguided attempt to address
Checkstyle configuration issues fixed by:
80d51f409aa36f1a5505214eb4ac6e1128213c92.
JCLOUDS-742 Remove cloudonestorage provider
JCLOUDS-40 unasync atmos.
JCLOUDS-40 unasync azureblob; plus fold otherwise unused azure-common into it.
JCLOUDS-40 missing azure-common reference from azureblob.
JCLOUDS-296 unasync keystone used by swift derivatives and cloudfiles.
JCLOUDS-296 unasync legacy swift provider.
JCLOUDS-296 unasync legacy cloudfiles provider.
JCLOUDS-296 unasync legacy cloudservers provider.
JCLOUDS-296 unasync hpcloud storage provider.
Update mailmap for acole@twitter.com
Moved jclouds-chef to the main repo