Log Message:
* Install my-{huge,large,innodb-heavy-4G,small,medium}.cnf example files.
* Use PTHREAD_AUTO_VARS=no to disable linking to libpthread all programs
  and libraries, which is wrong.
* Set USE_LIBTOOL and GNU_CONFIGURE before including bsd.prefs.mk, so
  the test for _OPSYS_MAX_CMDLEN is not skipped.

Bump PKGREVISION to each package respectively
(mysql-client and mysql4-client), closes PR pkg/28162 and PR pkg/28222.