Speed up with SAX+DB Parse Security Data

[wied03]

After #13 is settled one way or the other, create sqlite tables to hold security data.

Take all of the XML data and persist in tables.

Possibly use ETAGS, etc. to see if the XML file has changed before doing the download. If we do the download, then drop the contents of the tables before proceeding.

Use an XML SAX parser to populate the DB tables to avoid putting the entire DOM tree in memory.

[wied03]

Might not need a DB at all, may just be able to SAX parse and check each entry