Add ability to use "getent" binary for users look-up on current system.
Add ability to use "getent" binary for users look-up on current system.

This is to solve a problem where Puppet runs are slow due to Facter adding to the
sheer run-time, especially where LDAP is being used to provide source of truth about
system users.  There is a possible issue with the "user" type in Puppet which causes
this slowness.

Signed-off-by: Krzysztof Wilczynski <9bf091559fc98493329f7d619638c79e91ccf029@linux.com>

kwilczynski/facter-facts,benedikt-wegmann/facter-facts