Initial support for Occulus head-tracking via WebVR

Although there is no formal specification of the api yet, some Firefox and Chrome devs have published experimental builds implementing a close minimal api:
Firefox: http://blog.bitops.com/blog/2014/06/26/first-steps-for-vr-on-the-web/
Chrome: http://blog.tojicode.com/2014/07/bringing-vr-to-chrome.html
Fixes wintersmith alias non working, remove local cloning for remote (until we find a way to make sure local repo has gh-pages branch in local, and to latest update)
Adds new cwd option to latest grunt-git
Added support for VR rendering via WebVR

The distortion is now handled by the navigator.
We only retrieve the field of view and ideal render target resolution for the current hmd and setup a double camera node.
The dualcam has been updated, you can press f on a supported navigator with an oculus and it just works.
Merge pull request #85 from cedricpinson/hotfix/build_website

Hotfix/build website
Merge pull request #84 from Teybeo/feature/WebVR

WebVR
Added PointCloudViz to They Use OSG.js projects
Merge pull request #86 from jtorresfabra/web_project_addition

Added PointCloudViz to "They Use OSG.js" projects
fix grunt website, confirmed working
Fixes examples picking (display 2D position)
Merge pull request #91 from cedricpinson/hotfix/examples-picking

Fixes examples picking (display 2D position)
Fix viewport in manual vr distortion path

The viewport now has 1:1 ratio matching the canvas size.
Use old manual vr distortion path in dualcam example (for Cardboard)

When the 'Toggle VR' button is pressed and now WebVR hmd is found, it renders the scene fullscreen with the manual vr distortion path.
With this, you can use this example to watch VR on a Cardboard with a smartphone.
Fix small inconsistencies in Manipulators
Optimize Quaternion multiplication

Allowing mult(a, b, a) to do [a*b] and store in a
Add DeviceOrientation to eventProxy
Add FirstPerson Manipulator for DeviceOrientation
Add Orbit Manipulator for DeviceOrientation
Add Orbit Manipulator for Oculus
Disable DeviceOrientation by default

It isn't always relevant to have it enabled and should be enabled per use-case (Cardboard...)