a) Removal of private typedefs tulip_uint*_t, use standard u_int_*_t.
b) Change [Dd][Cc]21.4. to just 21.4., seems Dec has done this to all
of the drivers for all OS's. (Did they get in trouble with someone?)
[The few that remain can either not be eliminated, or are waiting for
additional driver functional changes that will remove them.]
c) Move some code from dc21040.h into the driver, later a whole block of that
code and more will move to devar.h, but for now this makes it easier
to study diffs.
d) Add a big bold comment to the README.de file about it not reflecting
reality anymore.
Note that these are all cosmetic changes and should be no functional
change in the driver whatsoever. If _anyone_ spots a problem introduced
by this please let me know ASAP!