- marathonctl now supports spawn/delete entity commands
- Fixed session state bug (was transitioning to Left every 5s)
- Fixed entity broadcast to detect Added<NetworkedEntity>
- Added AppCommandQueue pattern for app-level control commands
References: #131, #132
now the entire networking and persistence stack is zero-copy with
single-allocation, single-copy reads.
Closes#128
Signed-off-by: Sienna Meridian Satterwhite <sienna@r3t.io>