implement/fix issue #2: move additional binaries to "$PMODULES_HOME/sbin"

Pmodules/libpmodules.bash

@@ -3,10 +3,11 @@
 if [[  -z ${bindir} ]]; then
         local bindir=$(dirname "${BASH_SOURCE}")
 	bindir=$(cd "${bindir}"/.. && pwd)"/bin"
+	sbindir=$(cd "${bindir}"/.. && pwd)"/sbin"
 fi
 
 pmodules::get_options() {
-	"${bindir}/getopt" "$@"
+	"${sbindir}/getopt" "$@"
 }
 
 pmodules::check_env_vars() {