Adding photons to truth output and new trigger matching tool

We found that we needed truth photons in the file for our studies. We also wanted to validate the new derivation-level trigger matchingin EXOT27 with a view to moving to using it permanently.

I tested the new code with the MC and data ART tests. The output size for data was 11MB (compared to an input size of 4.1GB).

Cheers, Jon