s4-provision Remove setup_path, setup_dir and find_setup_dir

s4-provision Remove setup_path, setup_dir and find_setup_dir

We now have a reliable way to know the current location of the
templates: dyn_SETUPDIR, which is updated for both the in-build and
installed binaries.

This replaces the function arguments and the distributed resolution of
the setup directory with one 'global' function (imported as required).

This also removes the ability to specify an alternate setup directory
on the command line, as this was rarely if ever used and never tested.

Andrew Bartlett