* utils/hbmk2/hbmk2.prg
+ Added support for HB_INSTALL_PREFIX macros (recently introduced
in global.cf). Maybe it'd be better to not use this build-time
envvar at all.
Now that autoconfiguration is working pretty well, I think it may
be time to drop support for some envvars in hbmk2. In case of
HB_INSTALL_PREFIX it rather makes things more complicated.