Several of the closed issues were addressed partly in previous commits;
definitively close them with this, for the moment, final update to the crawler
package.

Ref:
    bitshift/crawler/indexer.py
            -move all `GitIndexer` specific functions (eg, `_decode`,
            `_is_ascii()`)from the global scope to the class definition.

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).

Add:
    bitshift/crawler/(crawler, git_indexer).py
        -move Codelet creation from the crawler to the git_indexer, in
        preparation for making crawling/indexing independent, threaded
        processes.

Mod:
    bitshift/codelet.py
        -modify documentation for the author instance variable.

Add:
    bitshift/codelet.py
        -complete docstrings, add filename to Codelet constructor.

Add:
    bitshift/codelet.py
        -add Codelet class with constructor.

    README.md
        -add SASS stylesheet documentation