* harbour/config/dos/owatcom.cf
* harbour/config/win/owatcom.cf
* harbour/config/linux/owatcom.cf
* harbour/config/os2/owatcom.cf
* harbour/utils/hbmk2/hbmk2.prg
* removed unnecessary linker options
* use 'SYS causeway' to enable causeway stub in DOS builds instead
of setting it manually. DOS users can also use DOS4G (default) or
PMODE (commercial) stubs.