Changes between #1696 and #1697

#1697 (Dec 3, 2019, 11:10:08 AM)

1. add projectile collides event, fixes #2075 (commit: 4f9d4a0) — agoodwin / detail
2. add Entity.can_tick property, fixes #2078 (commit: 00bda1b) — agoodwin / detail
3. upgrade new property system (commit: 6527ddf) — agoodwin / detail