This updates apt, apt_repository, command, cron, easy_install, facter,
fireball, git, group, mount, ohai, pip, service, setup, subversion,
supervisorctl, svr4pkg, user, and yum to take advantage of run_command
in module_common.py.

This patch adds an optional 'executable=' option to the raw command line to override the default shell (/bin/sh), much like the shell module does.

Since we use 'raw' heavily on equipment where 'command' and 'shell' are not (yet) working (and python may need to be installed first using raw) these improvements are necessary in order to write more complex scripts (with return code handling and separated stdout/stderr).

This change includes the following changes:

 - exec_command() now returns the return code of the command
 - _low_level_exec_command() now returns a dict, including 'rc', 'stdout' and 'stderr'
 - all users of the above interfaces have been improved to make use of the above changes
 - all connection plugins have been modified to return rc and stderr
 - fix the newline problem (stdout and stderr would have excess newlines)

In a future commit I intend to add assertions or error handling code to verify the return code in those places where it wasn't done. Since only the output was available, the return code was ignored, even though we expect them to be 0.

 - added terse syntax to modules.rst
 - added description of special variables to template module

 - fixed template (it was the template), adding indentation with Jinja2
 - added description of code examples to man-page template (was missing)
 - fixed fireball, cron, and debug module examples to confrom

implement lookup plugins for arbitrary enumeration over arbitrary things.   See the mailing list for some cool examples.

Teach fireball mode to disable the fireball by paying attention to 'minutes=N' (default 30) and do not let fireball module crash
on input.

- amended

The very first start of 'fireball mode', which uses ansible in SSH mode to deploy a ephemeral zeromq daemon (entirely optional) that is will die after
it is no longer used.  No key signing will be required.  At this point, development use only -- NOT complete.