Added support for multiple announce URLs to CLI

Completed a TODO in the CLI for Torrent creation: added support for
multiple announce URLs. Now a number of announcement URLs can be listed
with -a and will be added via Torrent.create (multiple announcement
list constructor existed previously).
Merge pull request #100 from chester8mcgee/master

Added support for multiple announce URLs to CLI
Added request strategy interface to abstract different strategy implementations.

Moved existing implementation into RequestStrategyImplRarest. Added an
addition sequential implementation.
Moved default request strategy to explicit constant.
Merge pull request #106 from cjmalloy/master

Added request strategy interface to abstract different strategy implementations.
Fixed file list for multi-file torrents.

File.listFiles() will return files and 1st-level subdirectories. Any
subdirectories in files parameter of Torrent.create(4) will throw an error.
Also, the intention was probably to do a fully-recursive search.

FileUtils.listFiles() only returns files and is fully recursive.
Merge pull request #109 from cjmalloy/master

Fixed file list for multi-file torrents.