[GRASS5] 5.4 release branch

[Paul Kelly]

I think the way forward now is to create a new branch in CVS and prepare 
5.4.0 from it. I'm starting to think now maybe 5.3.1 would be a waste of 
effort. I will create a new branch in a few days if there aren't many 
objections.

Here is my first rough draft of what to put in the NEWS file for 5.4.0, 
additions and corrections welcome:


Raster I/O re-write incorporating support for files > 2GB (Glynn)
Support for zlib compression in integer/CELL maps (Glynn)
g.pnmcomp: Added (Glynn)

PNGdriver: can now also write PPMs and optionally supports incremental writing of PNG after each display operation (Glynn)

Doxygen comments for improved Programmers' Manual (Markus)


r.colors new format for rules files (Hamish, Glynn)

nviz: some bugfixes (Glynn, Hamish)

Cygwin and Mac OSX shared library compilation working (Paul)

ps.map floating point legend fixes (Hamish)

rgb.hsv.sh bugfix (Glynn)
r.buffer nautical miles support (Hamish)
Raster map titles standardised to 1024 characters in all relevant modules and libraries (Hamish)


r.univar2 now operational (Hamish)
v.in.garmin.sh now operational (Hamish)

Various compiler warnings fixed (Glynn)

d.zoom fixes (Hamish)

Longer names for database, location and mapset allowed in start-up screen (Markus, Glynn)