[GRASS5] G3D modules

[Sören Gebbert]

Dear developers and users,
FYI, i made some small changes an bugfixes in my supported r3.* modules. 
These changes are in the CVS since two weeks, many, many thanks to Markus for that! 

Changes are:

r3.to.rast
* better error handling (G_unopen_cell)

r3.out.vtk
* added new flag "-o" -- the scalefactor effects the origin

r.out.vtk
* documentation update
* added new flag "-o" -- the scalefactor effects the origin
* added new flag "-p" -- pointdata support if no elevation map is given
* added new option -- elevation value for 2D data

r3.in.rast
* Bugfixing: wrong interpretion of the rastermap voidpointer.

and 
g.mremove
* added rast3d support

I updated my homepage 
http://www-pool.math.tu-berlin.de/~soeren/grass/modules/index.shtml . There are some screenshots and a small video now.

Best regards
Soeren