Concurrency fixes

  * Fixed: MapPanel, ModpacksPane and TexturePackPanel
    protect on*Add() with invokeLater()
    created unhandled exceptions

  * Fixed: LaunchFrame
    protect checkDoneLoading() with invokeLater()
    caused launcher to hang after "Adding Authlib to Classpath" message

  * Fixed: LauncherConsole
    protect onLogEvent() with invokaLater()
    preventive fix, no bugs seen yet
Merge pull request #715 from jikuja/fix_concurrency_v2

Concurrency fixes