(QENG-1400) Added support for host operations on a mac
(QENG-1400) Allowed yield blocks to get at actual command output, and returned unix style passwd user output

Mac's dscl output isn't formatted as the /etc/passwd expected by callers.  In order to go back to this, I changed the yield to use the
information after I formatted it.  However, this fails because the callers are relying on the parameter given to them having a .stdout
call and other things like it, so I've gone back to that old way, and allowed the unix formatting to still be used in the return
(QENG-1400) Removed comments and added in formatting feedback
(QENG-1400) Added spec tests for OS X host users and groups
(QENG-1400) Added yard documentation for OS X host users and groups
(QENG-1400) fixed whitespace issues in host file
Merge pull request #508 from kevpl/qeng1400_osx

QENG-1400 - Added OS X Support to Beaker's users and guests