BUGFIX: CanMove calls ZeroVelocity instead of setting it directly

TickedVehicle was setting the Velocity to Vector3.zero, but that's not
an option for AutonomousVehicle, just for Biped. Fixed it so that it
calls ZeroVelocity instead.
SteerForEvasion handles the case when there's no menace
Added SafetyDistance to SteerForEvasion

There's no need to have the creatures always avoid, and it looks more
natural if we can give them a distance at which they stop running around.
Implemented trivial PassiveVehicle

This is meant only as a way for other steering behaviors to track the
position and speed of items that are controlled by non-UnitySteer
methods, such as player-controlled characters.
Optimization: Moved agent displacement from FixedUpdate to Update

On profiling with a 100 agents, it's cheaper to run the displacement on
Update than on FixedUpdate.  For what it's worth, the cost seems to be
about the same for kinematic and non-kinematic rigidbodies -
non-kinematics are cheaper to translate, but incur an added cost on the
Physics.simulate call.

Also replaced some leftover references of transform for the cached value,
and added profiling code.
BUGFIX: Silly SteerForEvasion _sqrSafetyDistance bug
DetectableObjects cache the transform on a public property

Previously we were just caching it on a protected _transform, but this
allows us to read it from the steering behaviors as well, without having
to cache it themselves.

I'm open for comments on how people feel about naming conventions? Should
this type of property be called Transform, CachedTransform or something
else?
Optimization: Caching rigidbody on Vehicle, using it for Mass

Just noticed because of a tangentially related forum post that I was
using the rigidbody accessor on Mass, instead of a cached value. Moved the
current cache from TicketVehicle to Vehicle.
SteerForWander no longer returns a purely lateral vector

On its previous incarnation, directly descending from the OpenSteer
implementation, SteerForWander was returning a purely lateral vector. This
means that a vehicle with no other behaviors than SteerForWander would
never actually move, just stand there.

Also added blending the random values into an accumulator, to avoid very
severe turns that made the agents look like they were having a seizure.
Merge commit '45e8f3f5583c2c7100fd75bcc1758a960968a636' into development
Merge commit '52f363b93dc0f61582d110a75a3c4c8bd709dcf7' into development

Conflicts:
	Behaviors/SteerForEvasion.cs - Reason: using a Transform instead of a Vehicle -> needed to change Position to position
Merge commit 'd1d05dd022b793e04311cbe14dbe5e60cf685f87' into development
Merge commit 'dc2f3941115a0689f23f51e6046c620a8f409e4c' into development

Conflicts:
	Behaviors/SteerForWander.cs - ignoring changes, because I already reimplemented SteerForWander in a proper way