Collision detection working properly
Let browsers handle rendering style

Fixes ugly rendering in Firefox at cost of render speed.
After playing with a few different settings of `shape-rendering` it
seemed best to let the browser itself handle it.  We'll need to regain
performance elsewhere.
Merge branch 'release-0.4.1' of https://github.com/GraphAlchemist/Alchemy into release-0.4.1
Can create new nodes and edges
Remove debugger and console.log
Fix zoom/pan

I feel like we fix this every 2 days or so.  If it happens again we'll
have to find another way to write Alchemy::getInst() to where it doesn't
mess up.
Merge pull request #512 from MDCox/release-0.4.1

Collision detection; improved Firefox rendering