Filter 1.4.6_pre from MCNostalgia
Disable forge changelog button when there's no changelog
Make statusbar version display better
Merge branch 'dev' of https://github.com/Forkk/MultiMC4 into dev
Pass env vars to prelaunch and postexit commands properly.
Make the build number an actual visible variable.
Merge https://github.com/Orochimarufan/MultiMC4 into dev
Fix problem with running from an instance shortcut while automatic update checks are enabled.
Nuke obsolete forge version guessing.
Merge downgrade and update tasks, fix MCNostalgia.
Add states and state messages for the MCNostalgia update steps.