build fix to use junit/jaf/javamail reference files

Build fix to use junit.jar, activationjar, mail.jar files from locations
described at  "build15+" script.  Simple classpath reference didn't seem
to work with JDK 1.5
Clean ECGOST3410NamedCurves initialization

A new helper function, and calling it to initialize each curve.
X9ECParameters shared much of the ECDomainParameters functionality

The X9ECParameters is really a thin wrapper over ECDomainParameters,
although it was implementing same stuff that ECDomainParameters did.
Common ECNamedCurveTable tools for all system uses

The org.bouncycastle.asn1.x9.ECNamedCurveTable  has the global
static registry of known curve named, OIDs, and parameter
definitions.

The org.bouncycastle.jce.ECNamedCurveTable gets JCE specific
ECNamedCurveParameterSpec record out of that global database.
Moved all "XXXXNamedCurves.getYYY()" to use ECNamedCurveTable.getYYY()

All places not needing their own XXXNamedCurves class references are
using common getter tool.
Allow any ECC curves to be used at PGP, not only NIST curves