also added use warnings and strict

also fixed all reported errors by these, but work is still needed.

stuff like

sub thingy {
        my $thing = shift;
        my $stuff = $thing->os_ver();
        if ($stuff =~ /check/) {

-> newer perls (or perhaps just my config somehow) seems to prefer

        if ((defined $stuff) && ($stuff =~ /check/)) {

instead.

or perhaps i just don't understand autoloader magic & return type nuances.

Changes

@@ -4,6 +4,7 @@ Version 3.69 (2019-xx-xx)
 
   * duplex support for ciscosb
   * report all vendor names in lowercase
+  * sprinkle "use warnings" and "use strict" around
 
   [BUG FIXES]