Modernized build information for the about ganymede dialog

The 'ant jars' task now generates a property file named
src/resources/arlut/csd/ganymede/common/build.properties whenever
jars are built.  This Java properties file contains the
date, jvm version, and hostname that the jars were built on.
Fixed up the release string generated by aboutGanyDialog, BuildInfo
Made BuildInfo load the build-time metadata at system startup
Sped up BuildInfo.getReleaseString() as much as possible

The 'About Ganymede' dialog was slow to come up, so we're now doing
as much as we possibly can to get everything ready up front.