Pass options through on include

Pass template parse options down through include tags. This will make them use the correct parser, as well as respect profiling and (eventually) line number options.

This PR can supersede #420 since it solves the same problem (I also included the test from there). It solves it in a way that is more general and also is easier to integrate with #419.

@fw42 @jasonroelofs 
Would we ever want to not pass down the `:locale`?