o GRASS text mode startup

  "grass57" starts up d.m by default (if not first time user).
  "grass57 -text" will start up in text mode.
  "grass57 -tcltk" or "grass57 -gui" will start up in tcltk mode.

  You can use alias "grass57" to "grass57 -text" to use text mode by default.
  Or set env var GRASS_GUI=text.


o GRASS non-interactive startup examples

  You can startup grass57 non-interactively using some env variables.

  	LOCATION
	GISDBASE
	LOCATION_NAME
	MAPSET

  LOCATION var overrides GISDBASE/LOCATION_NAME/MAPSET location.

  ex1)
  	export LOCATION=/usr/home/grass/usr/data1/loc1/map1
	export GISDBASE=/usr/home/grass/usr/data1
	export LOCATION_NAME=loc1
	export MAPSET=map1

	grass57 -	# non-interactive startup using LOCATION location

  ex2)
	export GISDBASE=/usr/home/grass/usr/data1
	export LOCATION_NAME=loc1
	export MAPSET=map1
  	
	grass57 -	# non-interactive startup using
			# GISDBASE/LOCATION_NAME/MAPSET location


  Also, the first argument of grass57 can override these env vars.

  ex3)
  	export LOCATION=/usr/home/grass/usr/data1/loc1/map1
	export GISDBASE=/usr/home/grass/usr/data1
	export LOCATION_NAME=loc1
	export MAPSET=map1

	grass57 /usr/home/grass/usr/data2/loc2-1/map1-1
			# non-interactive startup using
			# /usr/home/grass/usr/data2/loc2-1/map1-1 location

  ex4)
	export GISDBASE=/usr/home/grass/usr/data1
	export LOCATION_NAME=loc1
	export MAPSET=map1
  	
	grass57 /usr/home/grass/usr/data2/loc2-1/map1-1
			# non-interactive startup using
			# /usr/home/grass/usr/data2/loc2-1/map1-1 location

  ex5)
  	export LOCATION=/usr/home/grass/usr/data1/loc1/map1
	export GISDBASE=/usr/home/grass/usr/data1
	export LOCATION_NAME=loc1
	export MAPSET=map1

	grass57 map1-1	# non-interactive startup using
			# GISDBASE/LOCATION_NAME/map1-1 location

  ex6)
  	export LOCATION=/usr/home/grass/usr/data1/loc1/map1
	export GISDBASE=/usr/home/grass/usr/data1
	export LOCATION_NAME=loc1
	export MAPSET=map1

	grass57 loc2-1/map1-1
			# non-interactive startup using
			# GISDBASE/loc2-1/map1-1 location


  Any suggestionss to <grass4u@gmail.com>

