crabat code cannot be shared across experiments

[goatface]

crabat presently has too many in-line declarations of specific experiment parameters and even histogram names. We need to export these experiment-specific declarations and variable setting to other files and programs, so that we can share the basic analysis code without always having to go in and fix lots of experiment specific details.

[goatface]

This is slowly getting solved by moving as much of the per-experiment details into Analyzer_config.cxx but it's not clear what to do about things in run.cxx and run.h (like the names of histograms, and run number filtering, etc)

[goatface]

Present gating overhaul addresses a large portion of this issue. The gating overhaul is still underway, but the basic functionality is implemented and tested to work.