Fix output summary.
Use command-line parameters to define directory for states and chains.
Ignore chains and states default directories.
Add base implementation for torrent site filters.
Use base class for kat.ph torrent site filter.
Add Pirate Bay torrent site filter.
Fix path names in .gitignore.
Add example for a pirate bay chain.
Allow for both magnet and download URIs to be null.
Treat empty download URI as null.