Fixed a bug where a token bucket would not be initialized before trying to use it.

git-svn-id: https://plugins.svn.wordpress.org/broken-link-checker/trunk@880947 b8457f37-d9ea-0310-8a92-e5e31aec5664
Log when the plugin starts or stops work()'ing.

git-svn-id: https://plugins.svn.wordpress.org/broken-link-checker/trunk@880951 b8457f37-d9ea-0310-8a92-e5e31aec5664