Merge remote-tracking branch 'upstream/master' into missile-lua

Conflicts:
	src/Ship.cpp
Use the distance facilities for missile explosion.

This changes the behaviour of missiles : they now spawn without target,
and will explode whenever a body enters a 100m radius, to the exception
of the missile owner.
Missile: the missile must be armed before it starts actively scanning for targets

It still explodes on collisions and laser hits, though.
Add a Lua interface to arm a missile
Missile: remove the safety for the owner, and act accordingly when launching
Merge branch 'master' into missile-lua

Conflicts:
	src/LuaShip.cpp
whitespace fixes
make isArmed an attribute instead
make sure the name arg is actually a string