v0.22.0-beta: A bugfix, some optimizations, and a set of new flags

For SpongeAPI 7

A shave and a haircut.

This update fixes console spam issues with explosions and a really
obscure consistency bug with damage protection.
Flags have also been optimized to be faster than before, because when i
originally wrote them i was really dumb.

Finally, because I optimized flags, there are now a whole bunch of new
entity flags, which allow much finer control over entity related events.

I'll have the documentation up at some point, but for now, feel free to
experiment!

Thanks all for sticking with me for so long. I know it's been a long
bumpy ride, but I really still wanna see this project through.