UI: optimize ship explosion effect
UI: optimize ship destruction effects and mining vector
UI: optimize ship trajectory gfx
UI: optimize / improve ship trail gfx
UI: implement Location#update
UI: use Location update method in motel callback

Location is now simply updated on server callbacks and
never overwritten
UI: add mechanism to follow ship with camera

To activate, select a ship and click 'follow' in the entity
details container.

To disable click 'stop following'
UI: few comments updates
UI: clear following location on scene changes