Add get_selections() and set_selections() for dpkg.

This module will enable to freeze a package at a certain version, with the "hold" state.
Add TODO, amend later... FIXME.
Merge my dpkg-selections branch with develop.

Resolved conflicts in modules/apt.py.
Fix merge mistake.

urllib2 and json is part of standard Python.
Use yaml.safe_load()
Add another TODO
Use code-block

As per @terminalmage suggestion.
Initial addition of fileserver event

This event is intended to "notify" salt that there are changes to the underlying fileserver module. This can be used to (for example) trigger a module sync within the reactor system-- but really you can do whatever you want with it.
Fix state.show_top to return the exact data as used by state.highstate
Collect with_communicate value in consistent and concise way

Just happened to be reviewing this code to see what it does...

There was a pop for stdin, but very verbose test for with_communicate
add execution and state modules for finding/killing procs by name
Added policy support to rabbitmq module

Added methods for:
 - list_policies
 - set_policy
 - delete_policy
 - policy_exists
Added state for checking rabbitmq policies are present or absent
Merge branch 'patch-1' into feature-rabbitmq_policy
Added reference url in comments of policy methods
add doc on fire an event, add commas to improve readability
Add an anchor to the enable Travis-CI note.
Handle pip versions lower than 1.2 when parsing the package using `pip.req`.
Instantiate a logger object to log.
Added mocked pip installation test-case for when pip's version is `<=1.1`