Added module to handle rabbit policies [1]

Used quite a bit of the existing rabbit modules provied by @chrishoffman.

[1] https://www.rabbitmq.com/parameters.html
Cleaned up docs just a smidge

Mostly added periods where missed, and corrected /vhost spacing.
The setting of params via dict or string by tags

Updated per @mpdehaan suggestions.
* Rather than passing in JSON, supply the policy options as a hash
  or string.
* Bumped version_added to 1.5.
Handled string/dict the ansible way
Added existing_only options to skip creating new files on receiver
Added -FF flag to rsync invocation in synchronize

The `-FF` option causes rsync to look for files in the source directory named `.rsync-filter` and uses them to filter directories underneath them. If no `.rsync-filter` files are found, the behavior is identical to the command run without the -FF option. This flag does not sync the .rsync-filter files themselves.

This change should be backwards compatible and not produce surprising behavior for users, since they are unlikely to create `.rsync-filter` files unintentionally.
Added note about .rsync-filter files, with example
Fixed a typo.
Add ability to specify a VirtualIP ID for sharing a VIP with another LB
Add version_added for vip_id
Added ability to start and stop existing EC2 instances.
Initial commit of rax_keypair
Utilize ansible.module_utils.rax
Don't import novaclient, exceptions are available via cs.exceptions
Added version_added
now handles default and allaows for either shorthand entry or specific
fields per entry section

the default option works both when added to entry or as stand alone.
Signed-off-by: Brian Coca <briancoca+dev@gmail.com>
Add rule group_name parameter whose value can reference containing group name.
Check for group_name and cidr_ip.
rds module: add snapshot capabilities

Add the ability to create snapshots and restore from them
Make instance creation, deletion, restore, and snapshotting idempotent
(really helps testing a playbook if you can run it multiple times)
Add -I/--interpreter argument to test-module