Styles and Data hooked up

Removed nodeStyle.coffee and edgeStyle.coffee as they were unnecessary.

The work that was done in them is now handled in svgStyleTranslator, which is a set of utility functions that are called to evaluate the styles of nodes and edges directly by the model.  Because svgStyleTranslator is renderer specific it has been moved to the drawing folder, but may later be moved to something like alchemy/drawing/renderers/svg/styleTranslator.coffee.  Since svg is our only renderer right now, that super-enterprisey folder tree isn't necessary quite yet.

Clustering, curved edges, captions, and directed edges all work! Woo!