Hits sometimes cause segfaults?

[zbanks]

Really hard to reproduce.

Also sometimes solid hits don't remove themselves.

-Zach

[zbanks]

Steps to reproduce:

• Hook up light strips so the output code fires -- causing the hits to get updated in two separate threads
• Add just a few hits

struct active_hit needs some type of locking system to get removed. Probably only .update should be able to remove the hit.

[ervanalb]

I think we need to do a thorough review of the threading and come up with a good locking strategy

[zbanks]

Hits are killed