In util/texi2dvi, don't try to re-exec under /bin/ksh, and improve the
test for whether "local" works.  Now ksh93 is correctly detected as
a shell that does not have a working 'local' command.

Use REPLACE_SH to edit the #!/bin/sh line in util/texi2dvi, to make
it use the value of ${SH} instead of /bin/sh.

Set PKGREVISION=1.

(apb)