Release v0.3.0-alpha

This is an alpha version of the new 0.3.0 launcher.
It's incomplete but usable, so I'm releasing it.

Some of the features added with the new Launcher:

• Single APK with just the AlephOne engine
• Download (or import) and install any AlephOne scenario
• Install custom plugins
• Export/Import scenario data (save files, replays, preferences, ...)

Bug fixes:

• Music now plays correctly for M1 and other scenarios
• Full screen HUD is now supported (as well as other plugins)

Known Issues:

• Running a different scenario will require the app to be closed first because of #35