First attempt at building a server pack

Upgraded Forge to 10.13.4.1558; added the Forge Installer to set up the
basic server directory; added templates for certain server config files;
set up makefile rules for building the server pack

scripts/launch.sh.template

@@ -0,0 +1,6 @@
+#!/bin/sh
+MEMSZ=2G
+PERMSZ=256m
+FORGEJAR=@FORGEJAR@
+
+exec java -Xmx$MEMSZ -XX:MaxPermSize=$PERMSZ -jar $FORGEJAR