RT3544: Restore MWERKS for NetWare

Reviewed-by: Richard Levitte <levitte@openssl.org>
RT3548: Remove some obsolete platforms

This commit removes BEOS.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Fix yet anoither 'make clean' breakage.

Reviewed-by: Tim Hudson <tjh@openssl.org>