A couple fixes for setup module

If ip is not found in either /sbin or /usr/sbin, this will return
an empty result.  It seems extremely unlikely that a linux system will
not have iproute2 installed

Specify full path to ip and add third argument 'show' to be explicit
about requested action.  This goes from 'ip addr' to
'/sbin/ip addr show'.

Add module common code to allow it to be easier to indicate whether arguments are mutually exclusive, required in conjunction, or whether one of a list of arguments is required.  This simplifies writing Python modules.

Make pep8 tests run against the library directory as well, and associated tweaks (mostly to indentation) in the library
directory.

Add openvz detection to virtualization facts, and some cleanup

Remove tests that involve network effects -- makes things faster and they are not really deep tests here either way.

Various retooling of the internal code behind inventory pattern matching in support of pending support
for host ranges.

add the limit option, which can be used to further confine the patterns selected by "hosts:" in ansible-playbooks
to an additional pattern (a subset) specified on the command line.  For instance, a playbook could be reusable
and target "webservers" and "dbservers", but you want to test only in the stage environment, or a few boxes at a time.

Add ability to store and access module results later on in the play.  See examples/playbooks/register_logic for details.

Given user report that EL5 sudo does not support '--', remove it, and things seem to still work fine.

let me know if this breaks any other boxes.

Update file module to not recurse when setting ownership