Updated to support new crawl command.
Added new 'crawl' command.

Crawling is done with 'crawl' instead of --crawl or -w

Usage:

./cosa.rb crawl
	- Resume crawling from the first item in the queue.
./cosa.rb crawl http://www.example.com [-options]
	- Cosa will start at this address and crawl every page on the site.
./cosa.rb crawl http://www.example.com/directory/ /directory/page/ [-options]
	- Cosa will start at 'http://www.example.com/directory/', and then
	  only add links to the queue if they contain the pattern
	  'http://www.example.com/directory/page/'.
Fixed a crash related to ill-formed links.