Clean up crawler/, fix minor bugs.

Add:
    bitshift/codelet.py
        -add name field to Codelet.

    bitshift/crawler/crawler.py
        -fix previously defunct code (which was committed at a point of
        incompletion) -- incorrect dictionary keys, etc..
        -reformat some function calls' argument alignment to fit PEP standards.

    bitshift/crawler.py
        -add sleep() to ensure that an API query is made at regular intervals
        (determined by the GitHub API limit).