inert atoms fall through to bottom
initial commit on synapses
added levels 18, 19, 20
added checks for synapses and receptors for level success; and restart button
hooked up restart button
fixed shadow radius under molecule view
radioactive atoms now drawn separately
draw electrons in new color
radioactive atoms work pretty well
atoms fall on command (that was faster than planned)
improved levels, removed alert
fixed falling order and falling bug
some auto-layout stuff
more autolayout constraints
and yet more auto layout stuff
changed number of moves to number of atoms; fixed radioactivity bug