Concerto: Lookahead is broken

Because of the way Regulex designed it's parser we have to have a system to look for the next node and if lookahead perform both nodes together, not like this:

<img width="279" alt="screen shot 2017-08-22 at 1 24 09 am" src="https://user-images.githubusercontent.com/2157285/29537915-c525d8e4-86d8-11e7-8f19-47e94857ec81.png">
