patches have been applied yet, but it's a start. The backends
	  are not installed as shared libs but as add-ons, which are shared libs
	  but in a specific folder in [/system|~]/config/add-ons/ named SANE/.
	  The install target has been changed to account for this,
	  Some files don't exist in BeOS/ZETA (ipc.h, ...).
	  Bbackend function names get a prefix, I suppose to avoid namespace clashes.
	  Though we do have a libdl to implement dl_open, the native way is prefered.
	  Added a --with-docdir= configure arg.
	  BeOS has a broken get[name|addr]info() from bind. This is fixed in ZETA R1.
	  libtool needs -no-undefined. Various VPATH fixes.
	  Check for <be/drivers/USB_scanner.h>, but not used yet.
	  No S_IFSOCK (sockets are fds to /dev/net/api). Stub pio code, untested.
	  Patch from Francois Revol <revol@free.fr>.