support scripts: Add /usr/bin/env in shbang that is nearly (not really)...

support scripts: Add /usr/bin/env in shbang that is nearly (not really) portable way to solve the path.

support/correct_msgid

-#!/usr/bin/perl
+#!/usr/bin/env perl
 # -*- indent-tabs-mode: nil; -*-
 # vim:ft=perl:et:sw=4
 

support/git-set-file-times

-#!/usr/bin/perl
-use strict;
-use warnings;
+#!/usr/bin/env perl
+# -*- indent-tabs-mode: nil; -*-
+# vim:ft=perl:et:sw=4
 
 # Sets mtime and atime of files to the latest commit time in git.
 #
 # This is useful after the first clone of the Git repository BEFORE you
 # do any building.  It is also safe if you have done a "make distclean".
 
+use strict;
+use warnings;
+
 my %ls;
 my $commit_time;
 my $prefix = @ARGV && $ARGV[0] =~ s/^--prefix=// ? shift : '';

support/pod2md

-#!perl
+#!/usr/bin/env perl
 # -*- indent-tabs-mode: nil; -*-
 # vim:ft=perl:et:sw=4
 

support/xgettext.pl

 #!/usr/bin/env perl
+# -*- indent-tabs-mode: nil; -*-
+# vim:ft=perl:et:sw=4
 
 use strict;
 use warnings;