Add option for expanding remapped Spigot

Created from https://github.com/EcoCityCraft/Spigot-Server by running https://github.com/MinecraftForge/Srg2Source:

py remap-craftbukkit.py --cb-dir=../../CraftBukkit --fml-dir=fml --out-dir /tmp/out --skip-output-archive --skip-finish-cleanup --skip-compile

..until MCPBukkit can be setup automatically remap Spigot's patches.