Processor module for writing the results of successful fetches (and
perhaps someday, certain kinds of network failures) to the Internet Archive
ARC file format.
Assumption is that there is only one of these ARCWriterProcessors per
Heritrix instance.
author: Parker Thompson
Writes a CrawlURI and its associated data to store file.
Currently this method understands the following uri types: dns, http,
and https.
Parameters: curi - CrawlURI to process.