Implemented follow-symlinks feature for S3.

Added unit and integration tests along with PEP8 reformatting for
the entire file.
Added --[no]-follow-symlinks options.
EMR: Add cluster state filters shortcut --active, --terminated and --failed in list-clusters command.
Removed quietly skipping over bad symlinks.
Merge branch 'kyleknap-sym_dev' into develop

* kyleknap-sym_dev:
  Removed quietly skipping over bad symlinks.
  Added --[no]-follow-symlinks options.
  Implemented follow-symlinks feature for S3.
EMR: Removed Version from Applications schema.
Update changelog with latest changes
Update changelog with new features
Update tab complete test with route53domains command
Bumping version to 1.3.25
Merge branch 'release-1.3.25' into develop

* release-1.3.25:
  Bumping version to 1.3.25
  Update tab complete test with route53domains command
  Update changelog with new features
Fixed URL decoding bug.

Keys were being decoded twice when syncing from
s3 to s3.
EMR: Added default configuration for create-cluster. Fixed create-cluster.rst format. Added shortcut options --instance-type and --instance-count to --instance-groups.
EMR: Add MasterPublicDnsName in describe-cluster output.

EMR: Refactor sshutils.
EMR create-cluster: Change --visible-to-all users to be true by default.
Removed hard-coded BucketListerDecodeKeys.
Added a unit test to ScopedEventHandler.
Merge pull request #862 from kyleknap/encoding_bug

Fixed URL decoding bug.
Updated changelog with updates.
Merge pull request #863 from kyleknap/develop

Updated changelog with updates.