ModMenu Beta

This is getting annoying, I hope this is the last time I deal with this refmap bug.

• Updated mappings, which somehow fixed the crash issue.

• Removed dependency on GSON and Guava.
• Fixed a rare crash in certain environments.

Changes:

• Latest dev build, a few modders have had fewer crash issues with this compared to beta.7.

Changes:

• ACTUALLY fixed the crash.

I wasn't able to test myself cause I wasn't affected by it. :/

Changes:

• Actually fixed that nasty startup crash.