[GRASS-dev] Driver changes

[Glynn Clements]

I've just committed some changes to the layout of the driver code. 
Specifically, the display/drivers/lib directory has been moved to
lib/driver, while the bulk of the PNG driver has been moved into a
separate library in lib/pngdriver.

It shouldn't have any impact from the perspective of either
application code or the user, but the changes to the layout (and the
corresponding changes to the Makefiles) are signficant enough that I
could have missed something which could cause compilation problems.

I would appreciate it if people could report successful compilations
after having updated to the new code, so that I can get an idea of
when it's had a reasonable amount of testing. I don't want to commit
the next phase (integration of libpngdriver with libraster) until any
problems with the latest changes have been ironed out.

-- 
Glynn Clements <glynn at gclements.plus.com>