Add RayCast item
Add RayCast example
Install plugin in a version directory to allow parallel installable versions
dropped unneeded check for importPath
Update examples
turn hard-coded 'pixelsPerMeter' into Box2DWorld's property
Merge pull request #51 from ElderOrb/master

turn hard-coded 'pixelsPerMeter' into Box2DWorld's property
Merge pull request #49 from kenvandine/parallel_installable

Install plugin in a versioned directory to allow parallel installable versions
Merge pull request #47 from folibis/examples

Update examples
Fixed crash when starting the 'mouse' example

Since the world is not known during initialization but only once things
are being created, the joints also do not know the value of
pixelsPerMeter during initialization.

The solution implemented here delays the creation of a b2JointDef
instance (along with any necessary conversions) until the point where
the joint is actually being created.

Only the MouseJoint has been fixed, the other joints would have to be
adapted in the same way.
Merge pull request #32 from folibis/raycast

Add ray cast functionality
Simplified raycast API

* Added World.rayCast function, taking a RayCast object and the start
  and end points for the ray.

* Removed RayCast.point1, RayCast.point2, RayCast.world, RayCast.repeat
  and RayCast.running. All these properties can be trivially implemented
  on the QML side.

* Renamed RayCast.result to RayCast.maxFraction

* Renamed RayCast.onCast to RayCast.onFixtureReported

* Adjusted raycast example accordingly
Fixed up the DistanceJoint

The main change is to not make it crash when its anchors or length are
set before it is being created. In addition, the choosing of defaults
for localAnchorA, localAnchorB and length has been improved.

Also fixes changed signal in Box2DDistanceJoint::setLocalAnchorA.
Fixed up the FrictionJoint

Made sure it doesn't crash when anchors are set before the joint is
created. Separated defaults for localAnchorA and localAnchorB.
Updated GearJoint for consistency

It wasn't crashing, but this just makes the creation style the same as
the other adapted joints.
Merge pull request #57 from bjorn/simplify-raycast

Simplified raycast API
Fixed up the MotorJoint

Don't crash when setting linearOffset before joint creation.

Also, when linearOffset and angularOffset are set before joint creation,
their values now actually take effect whereas before they were ignored.
Fixed up the PrismaticJoint

* Don't crash when initialized before creation
* Added PrismaticJoint.referenceAngle
* Changed PrismaticJoint.axis to PrismaticJoint.localAxisA
Fixed up the PulleyJoint

* Don't crash when initialized before creation
* Added defaulting to center of mass for local anchors
* Added defaulting of lengthA/lengthB to the difference between local
  anchors and their respective ground anchors
Fixed up the RevoluteJoint

* Don't crash when initialized before creation
* Added RevoluteJoint.referenceAngle
* Fixed default behavior of localAnchorB in case localAnchorA is set
  to a value different from the center of mass of bodyA (also applied
  to FrictionJoint and PrismaticJoint)