[Halld-offline] DL1Trigger added

[David Lawrence]

Dear Offliners,

 On Friday I pushed a change that added a factory that creates DL1Trigger objects. (See details of pull request
at link below.) This was to address the newer data sets that may contain more than one active trigger type.
The class has 2 members:

gtp_latch
fp_latch

These are words whose bits indicate the active trigger(s) for the event as reported by the Trigger Supervisor.
>From discussions with Alex, I understood that older data did not have a standard assignment for the bits (e.g.
the PS trigger may be one bit in one set of runs, but another bit trigger bit in another set of runs). He is fixing
this for future data (and perhaps some recently acquired data?). The permanent assignments will be published and
added to DL1Trigger as an enum once they are finalized.

https://github.com/JeffersonLab/sim-recon/pull/171/files

Regards,
-David