#31 add configuration management feature to cpacman

Why
---
- None of the systems listed at `Wikipedia Comparison of OpenSource CMS <http://en.wikipedia.org/wiki/Comparison_of_open_source_configuration_management_software>`_ are close enough to the sysadmin working style
- Use the existing CPacMan framework

What
----
Edit a configuration file for one or multiple servers from the CPacMan machine.

How
---
Use Vim's 'netrw' plugin combined with RCS on CPacMan machine.

Syntax
------
::

edit_config.py -h myserver -m mycomment path-to-file

Workflow
--------
What CPacMan does in the background:

#. if "myserver" is part of a cluster it will diff to make sure all files all identical
#. 'co' the file from "/opt/cpacman/servers/myserver/path-to-file" (if it's a cluster it does it for all servers) (if "path-to-file" does not exist it will create it)
#. starts Vim with 'scp://' (netrw plugin)
#. (while editing, saving is being handled by the "netrw" plugin, this way we can test our changes on "myserver" e.g. Apache configurations)
#. upon exiting from Vim 'ci' using "mycomment" (if a cluster do it for all servers and 'rsync' (to preserve file attributes) to all cluster members)
#. update "comment_rpm" with in a similar fashion as it does for package installation