Log Message:
Completely overhaul the zsh package.

 - Get rid of useless Makefile.common and pointless variables since there is
   no longer a zsh-current package.

 - Remove non-standard per-OS non-checksummed patch file in FILESDIR.
   Integrate it correctly in the normal way.

 - Ensure our patched configure.ac is actually regenerated.

 - Use REPLACE_INTERPRETER instead of homegrown subst replacements.

 - Remove esoteric and fragile configuration variables, a bunch of legacy OS
   based options, and simply depend correctly on terminfo and curses.

 - Remove custom test targets and requirements for root access, the test suite
   works fine as a non-root user and can be done in the normal way.

 - Use options.mk

 - Set maintainer to pkgsrc-users, uebayasi resigned.

Fixes build on at least SunOS.  Tested on SunOS, Darwin, NetBSD (with and
without the "static" option), and Linux.