added first version of pkgin, just does install, remove (for SmartOS)
add pkgin to list of package managers in setup
pkgin: change install/remove to not use return code of pkgin

pkgin always returns 0 so can't be used to tell if the install or remove
worked.  Instead this just queries the installed packages after
performing an operation.
pkgin: use module.run_command to run stuff

This also fixes an issue where some console output for packages I was
installing was creating invalid JSON because it contained single-quotes.
pkgin: add stdout to error message when shell commands fail
Merge pull request #1906 from szinck/devel

Add basic pkgin package management