Added h5bp default styles, but splitted these in smaller .scss partials for better modularity:

_h5bp-defaults.scss: good defaults
_h5bp-helpers.scss: helper-classes like .cleafix and .ir
_h5bp-print.scss: good default print styles

These files are truly optional. If you for example you use Compass, many of these styles are already available as mixins or placeholders.