Add 13w05b Minecraft 1.5 snapshot mappings obf <-> MCP 7.34
Generate 13w05b snapshot <-> CB 1.4.7 mappings

Created by chaining through MCP:

py chain.py 1.4.7/mcp2cb.srg 13w05b/mcp2obf.srg | sort > 13w05b/obf-to-cb147.srg
py reverse-srg.py 13w05b/obf-to-cb147.srg > 13w05b/cb147-to-obf.srg