crawler: expunged 'this' for cleanliness.
Halfway broken. Committing for merge.
Merge branch 'master' of github.com:cgiffard/node-simplecrawler

Conflicts:
	test/testcrawl.js
Asynchronous events are now supported by the crawler, and documented!

Tests also written for the new methodology.
Updated npm version, fixed a pre-push bug, and increased timeout on the test suite.