Small Bugfix Update

Here's a small bugfix update for the demo with things that came up since the last release. The changes are now live in version 0.33:

1. Fixed wrong XP drop rates in stage 2, which now makes it possible to reach much higher levels.
2. Launcher and Seeker can now be used to damage shields with direct hits.
3. Fixed wrong damage accounting for neutrals.
4. Rework target selection behaviour, to better handle the actual aim direction and ignore neutrals and projectiles by default.