Log the commands (command and arguments) executed via the execCmd
function, including commands run via iexecmd.

This can be useful in certain situations and like, login events,
should be logged as a notice-type message (for sites logging
LOG_NOTICE events, which is recommended).


git-svn-id: svn://irodssvn.ucsd.edu/trunk@5579 ea137bd6-aa86-47b6-b90d-b101d9f19a90