[Halld-offline] changes to FCAL reconstruction and CCDB

[Shepherd, Matthew]

HI all,

I submitted a few changes to the FCAL reconstruction
and CCDB.

First I put constants in the DB that act to turn off the
nonlinear photon energy correction that was happening
at the transition from DFCALCluster -> DFCALShower.
That will have the following effects:

* energy scale of high level photon analysis objects should
be approximately correct, i.e., the two photon invariant
mass should show a peak at the pi0 mass
* energy scale of MC will now be incorrect

This is obviously something that needs tuning post-calibration
to get desired performance from both MC and data, but
I think the current scheme is useful for bump hunters
who are looking at data.

The FCAL remains uncalibrated at the block level -- we're 
working on it.  So, don't expect sharp resolution yet.

I also increased the default minimum number of blocks
to make a cluster from 1 to 2.  This is helpful in
the later runs that were taken with a relatively low
DAQ threshold.  It suppresses single block noise clusters.

Matt

---------------------------------------------------------------------
Matthew Shepherd, Associate Professor
Department of Physics, Indiana University, Swain West 265
727 East Third Street, Bloomington, IN 47405

Office Phone:  +1 812 856 5808