dirname() does not behave the same everywhere, ... sigh
need to extend the search path for #include to include the directory
for the infile from the command line (if any) so that
$ pmcpp /some/path/root
works when /some/path/root contains
#include "pmns"
and pmns is really hiding in /some/path/pmns
pmcpp - tweaking following more testing
for the infile from the command line (if any) so that
$ pmcpp /some/path/root
works when /some/path/root contains
#include "pmns"
and pmns is really hiding in /some/path/pmns