updated FDC ASIC document

[Simon Taylor <staylor@jlab.org>]

Hello.

I've posted an updated version of the FDC ASIC document 
(GlueX-doc-1070-v2) to the portal.   This version has a gas gain 
calculation using an Fe-55 source and an extensive discussion of 
simulated pulses
for both protons and muons.

Simon