[GRASS5] g51 coor,topo formats changed

Hi,

I changed coor and topo formats to save some space (Bernhard, your 3 bytes
for line type are saved) and write/check file size.

=> necessary to create new binary files, if you experiment with g51.

Radim Blazek
Praga, Bohemia
--------------------------------------------------------------------------------
Petition for a Software Patent Free Europe:
http://petition.eurolinux.org/index_html?LANG=en