Added index_canary.html to test native support

Added index_canary.html to test native support in Google Chrome Canary
Changed parsing behavior: now exits at first match

Changed parsing behavior: now the algorithm for parsing sources exits
at first match, not at the last one. Tests were updated, and they’re
green :)
Releasing v4.0.0 - see change log
Merge branch 'master' into gh-pages