The implementations on top of OpenOBEX I've done so far all "guess"
the optimal size of data chunks to add as body headers (typically
something like "MTU - 200"). Would the attached patch for a new
OBEX_ObjectGetSpace function make sense that applications could use to
get a more precise value for what size body headers they can
successfully give to OBEX_ObjectAddHeader (the actual calculation in
the patch is directly taken from OBEX_ObjectAddHeader). Or is there
already a better/cleaner way to do this with the current openobex API?