[GRASS5] White spaces support

[Markus Neteler]

Hi,

I have commited some changes to CVS to support white space
to some extend.

GRASS:/tmp/grass data > g.gisenv
GISDBASE=/tmp/grass data
LOCATION_NAME=rmapcalcUTM
MAPSET=PERMANENT
MONITOR=x0
GRASS_GUI=text

GRASS:/tmp/grass data > pwd
/tmp/grass data
GRASS:/tmp/grass data > l
total 4
drwxr-xr-x    3 neteler  ssi          4096 Feb 27 16:12 rmapcalcUTM
GRASS:/tmp/grass data >

It's possible to start GRASS now with white spaces.

Hope that it doesn't break anything,
but the changes are just variable quoting in the start shell 
scripts.

Markus