Added logger plugin example
Revert to pre 0.9.0 release of Socket.io.
Only call plugins when needed
Fixes #91 - https://github.com/shakyShane/browser-sync/issues/91
Fixes #75 - https://github.com/shakyShane/browser-sync/issues/75
Fixes #106 - https://github.com/shakyShane/browser-sync/issues/106