Merge pull request #733 from Viper-7/master

CHANGED: Enabled kill minecraft button only when usable
manual merge of PR closes #712
fix derp in authlib helper that was causing issues on fallbacks
FIXED: mojang_vanilla updating even when pressing no
Merge pull request #734 from jikuja/fixes_for_1.3.10_v6

FIXED: mojang_vanilla updating even when pressing no
FIXED: Recommended version for vanilla MC pack