File format
 -----------

  The ASpringies file format is human readable.  Each line consists of
a  four letter command string,  followed  by the  parameters for  that
command.   The file must start with  the command "#1.0".  Each of  the
commands below is on a  line by  itself.  There  are  no  blank  lines
allowed.  The file must end in a newline.

  The file consists of the following commands:

	cmas <current "Mass" value>
	elas <current "Elasticity" value>
	kspr <current "Kspring" value>
	kdmp <current "Kdamp" value>
	fixm <boolean value for "Fixed Mass">
	shws <boolean value for "Show Springs">
	cent <mass id number of center mass>

  If there is no center mass  (i.e. - center of screen is to be used),
then the value of -1 is used.


	frce    <force id number> <boolean active> 
		<parameter #1 value> <parameter #2 value>

The <force id number> sequence is as follows:

	0 - Gravity
	1 - Center of mass attraction force
	2 - Center attraction force
	3 - Wall repulsion force


	visc <current "Viscosity" value>
	stck <current "Stickiness" value>
	step <current "Time Step" value>
	prec <current "Precision" value>
	adpt <boolean value for "Adaptive Time Step">
	gsnp <current "Grid Snap" value> <boolean enable>
	wall <boolean top> <boolean left> <boolean right> <boolean bottom>
	mass <mass id number> <x position value> <y position value> 
	     <x velocity value> <y velocity value> <mass value> <elasticity value>

  For each  mass,  the  <mass id number> must be  unique.  They do not
need  to be in any order.  If a  mass is fixed, then the  <mass value>
field is negated.


	spng <spring id number> <mass #1 id number> <mass #2 id number>
	     <Kspring value> <Kdamp value> <rest length value>

  For each spring, the <spring id number> must be unique.  They do not
need to be in any order.  The order of the <mass id  number>'s  is not
important.


  All  <values>  are floating  point  numbers.   All <id  numbers> are
positive integers, and  all  <boolean>  values  are non-zero/zero  for
True/False.  It  is  possible to feed ASpringies bogus values.  It may
produce  interesting or  amusing  side effects, but will  most  likely
cause an object to explode or ASpringies to crash.