Constrain nodes to layout bounds

Want to get rid of gravity and charge distortions so need to force them
to stay in the box. Not necessary for production since layout is
already set.
Physics tweaks to more acurately mirror production
Readme ToDo update
Merge constrain to layout
Set max width of chart

Otherwise the force skews it
Fix open div in IE8 fix

closing div was wrapped in the IE9 code.
Merge branch 'master' into production to close div