Ubuntu started to flag which as deprecated and it
seems which is not really standard and may vary
across Distro.
Drop the use of which and use the standard 'command -v'
for this simple task.
Which is still present in the prereq if some package/script
still use which.
A utility script called command_all.sh is implemented that
will just mimic the output of which -a.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>