Fixes for userpage issues, preview of karma awards

Sorry this isn't a simple fix for userpage issues, I'd already started work on karma awards by the time I heard.  To fix the userpage, just overwrite builder.py, listingcontroller.py, and template_helpers.py.

This does include an untested version of karma awards - it should be enough to get an idea of what the feature is intended to look like.  Do you think the UI is ok?