Naively quote original vim arguments

We assume no std* / fd* hocus-pocus

bin/vim-bx

 # run vim as you would
 my $real_vim = `/usr/bin/env -i which vim`;
 chomp $real_vim;
-my $cmd = join ' ', $real_vim, @ARGV;
+my $cmd = join ' ', $real_vim, map { "\"$_\"" } @ARGV;
 system($cmd) == 0
     or warn "vim failed: $!";