Add static file handling, templates with html5 boilerplate, rudimentary drawing function for visualization

This is an incremental update that supplies some scaffolding for next steps. Here is what is included in this pull request:

    1. Added static file handling and directories for static files (static/,  static/css, static/img, static/js)
    2. Configured a template `base.html` that is modeled after html5boilerplate
    3. Configured `handlers.py` to use jinja2 templating system.
    4. Changed IndexHandler to use template
    5. Created route, handler, and template to get twitter visualization working. There is a very basic drawing function that uses D3.js bubble packing. Lots of room for improvement, but should be pretty robust. 

Please let me know if you have any questions. sd