Added files in static (favicon.ico) as package_data in setup.py

When pip installing flower, `static/favicon.ico` is not copied in (because previously package_data only included files within a subdirectory of static). This results in the error:

    [E 131218 14:06:15 web:2148] Could not open static file '[rescinded]/lib/python2.7/site-packages/flower/static/favicon.ico'

The fix includes any files that are directly contained within the static directory.