Log Message:
Fix botched migration of PKG_OPTIONS from courier-mta/Makefile.common
into the Makefiles of the packages that include it:

(1) PKGNAME and PKG_SUPPORTED_OPTIONS clearly no longer need to be
    defined since the only code that used it in Makefile.common was
    removed.

(2) Package Makefiles need to properly define PKG_OPTIONS_VAR and
    PKG_SUPPORTED_OPTIONS prior to including bsd.options.mk.  Set
    them to the appropriate values to match the orginal names from
    before the botched migration.