Started GUI

Using kivy for now
Drawing

- child collision detection
- arbitrary placement based on mouse click
- Runtime editing of existing data
- Bond drawing
Periodic table

- Removed tutorial files
- Began adding popup periodic table
- Support for placing any atom
- Partial support for drawing bonds
Building a molecule

I'm having issues setting up lxml to play nice with kivy.  Might have to
pull the plug on kivy and switch to something else
Fixes for kivy

- Got it working in canopy
- Got lxml working
- Started removing all the global stuff and encapsulated it in my app
- Working support for drawing a molecule and storing it as a compound
object
Merge pull request #24 from Dannnno/GUI

GUI