Motel#normalize - parameterize ArgumentError raised
Motel#axis_angle - handle parallel vectors edge case

Calculates angle using arbitrary 3rd vector for axis
(cartiesian normal)
Motel#axis_angle - handle parallel vectors edge case

Calculates axis using arbitrary 3rd vector (cartiesian normal)
Fixnum#zeros - return the number of zeros in a fixnum
Style / formatting fixes

- print movement strategy using to_s in omega-cosmos-retrieve

- alias Motel::MovementStrategies::Rotatable#change_due_to_rotation?
  to rotation_stopped?

- small whitespace / formatting fixes
LinearMovement - extract checks into helpers

Extracts a few stop distance / coordinate related checks into
helper methods for reusability purporses
Add LinearMovement#facing_movement? helper

Returns true if specified location orientation is the same as the
direction of movement
LinearMovement#set_acceleration_from - accept array param
LinearMovement - incorporate elapsed time in acceleration

Previously full acceleration was applied on each movement.

This fixes mixin so as to only apply acceleration component
corresponding to elapsed time when moving
Motel::MovementStrategies::TracksLocation - parameterize max_angle

Previously max angle was statically set to Math::PI/4, this allows
invoker to specify it
Adds Motel::MovementStrategy::TracksCoordinates mixin

Similar to TracksLocation but this simply works on a fixed set
of coordinates (may change TracksLocation to use this at some
point). Tests still need tbd for this module (and recent changes)
Implement the "Towards" movement strategy

Incorporates similarities to linear and rotatable movement
strategies but will continuously try to move towards specified
target coordinates.

Will face target on approach though when within computed distance
will flip 180 degrees and decaccelerate so as to stop at target
(this functionality may be further parameterized at some point).

Specs still need TBD
Use Towards movement strategy to move ships in system
Support attribute specification in server registry #update

Use in various server-side update calls to limit scope to
intended attributes.