pyglet step1, create window and write text
pyglet step2, physics simulation with only atoms
pyglet step 2.1, stable frame rate
pyglet step 3, using batch to draw sprites
improved .gitignore
Can now create molecules and the test passes again.
supports reactions
Implemented key commands again and fixed memory leak

Memory leak fixed by not recreate vertexes for bonds every frame, instead
just change the position on the existing vertexes.
removed last pygame dependencies
removed unused import of pymunk.pygame_util
updated README and remove unused imports
updated .travis.yml to start a headless xvfb
All atoms in a molecule now share the same start pos

..to make the simulation smother.
Can now draw effects with pyglet
Aqueous molecules are no longer draggable
Game is closed properly when all level are done.
not possible to move atoms of screen
libcml: Atom.formalCharge defaults to 0
render electric charge on atoms