Make player system facet agnostic

update to allow generate worlds whitout default facets.
I looked trough comments to last pr of same name. and fixed what could
be. This if is necesary because not all world generators use default
facets.
small change to make class more readable

I moved definiton of variables before if satement. like suggeted.
tweaks to PlayerSystem

removed else, to make searching spawn point Universal
Fix NPE in DebugOverlay. Closes #1376
Fix checkstyle errors and related warnings
Merge PR #1381 by @msteiger - checkstyle fixes
Update module lineup in readme and further tweak some javadoc
Add linux protobuf compiler and make the grandlew task runProtobufLinux working.
Tweak task name to avoid ambiguous "gradlew run"
Make the isChunkValidForRender check a lot faster.

Half of the render time was spent to check if a chunk is valid for render.

By precalculating this value when the chunks change, the frame rate
increases for me at a certain world with view distance ultra from
about 40 to 50 FRPS.
Merge PR #1383 by @flo - chunk optimization (commit redo)
Fixed an issue which could have caused the FPS to stop updating.

The issue was that the resolution of the getRealTime values was so bad,
that it couldn't be used on all PCs for checkin when enough time has
elapsed.

This patch also changes it back to updating each frame for the following
reasons:

- The FPS number is already an average so usually the value doesn't change
  by much.
- Any large FPS changes should be eliminated by us in the long run
   -> there should be no spikes
- You can see the results of what you do instantly
   -> you don't need to wait for a half second
- You don't miss performance drops that occured only at a few frames
- If the numbers update so slowly it looks like the game is having
  issues to update the UI
Merge PR #1382 by @flo - FPS display fix
Mark chunks as ready in the tests.
Fixed restore of uncompressed chunks.

Storing uncompressed chunks is a feature that is disbled by default.
A test showed that it was broken.
Merge PR #1385 by @flo - test + storage fix