Rough update to 1.7.2

This (along the changes done in Guilib) allow to run in 1.7.2, tested in both SP and MP (with MCPC+), Forge 1019.

The network porting is rough and may be improved (in particular when MCPC aligns with Forge 1024), so do some variables which are still obsfuscated (latest Forge has also new MCP mappings).