[GRASS5] Long filename support enabled

[Markus Neteler]

Hi,

I have enabled now the long file name support (location
names, mapsets, map names) after fixing lots of hardcoded
lengths to the definitions in include/gis.h and include/imagery.h.

I did some tests, no problems so far except for some image
processing modules which still have limited name lengths
(see other mail concerning file clones).

Please report bugs if long names are still unsupported
in certain cases (developers please fix directly in CVS).

Length is now 256 chars.

Markus