Fix size calculation on laser shot entity - closes #104

Need to set collisionRadius on entity to get render pass culling to work
May be a few other purely visual entities that have similar problems.
Automatically download dependencies, if available, when installing OXZ

Dependencies already met won't be downloaded (e.g. if an OXZ depends on
ABC >= 0.4, and ABC 0.6 is installed, ABC 0.8 won't be automatically
downloaded)
Fix use of NSInteger as format argument
Fix use of OO_ENTER_OPENGL() in planetDrawable
Stop problems on ship library screen

Also fix bug with NPC shield booster removal
preserve scanner zoom across docking, witchspace and game saves
Set preservation of scanner zoom to nonlinear only
Make sure ECM delay timer is stopped before ship is destroyed
Make internal damage occur multiple times for very high-damage hits

Missile impacts may now damage several pieces of cargo/equipment
Use fallthrough instead of else in dockingInstructions

Because every branch of the if tree ended with a return statement, a
Sufficiently Smart Compiler complained that the fallback return was useless.
Removing the else clauses avoids the issue without changing logic or control
flow in any way.
Visual indication of ECM activity - scanner fuzziness
Merge branch 'master' of github.com:OoliteProject/oolite
Register ship forms should return to the interfaces screen when complete
Update changelog
Start on allowing scenarios to restrict OXPs

 - compiles
 - strict mode seems to work
 - loading works

Partial restrictions as yet untested
Mousewheel implemented for SDL builds.
Enabled mousewheel use for zooming in and out at the Galactic Chart screen,
Add mousewheel and chart mouse dragging
Fix planet not showing up on double click in chart
merge master