Add ec2_elb_lb for managing ELBs
Add health check parameter.
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
New lookup plugin csvreader
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.
Don't modify hgrc when running purge
Allow multiple users to use ec2 inventory scripts

Move the ec2 cache files from a shared /tmp location to the
user's ansible tmp directory.
Initial commit of rax_dns module
Add state attribute to description
Remove errant raise
Initial commit of rax_dns_record
Fail EC2 inventory better with restricted EC2 users

If a user has full EC2 access but no RDS access, the user
should still be able to query the EC2 inventory, although
will not obtain any information about any RDS instances.
Add ec2_key module.
Minor typos and remove extra dependencies.