Added frustum Culling feature
Mocked up the viewer to get working the CullVisitor in failing tests
Precreate Vec4 arrays in getFrustumPlanes function
Added the possibility to enable/disable frustum culling at node level. Unit testing added.
Added the posibility to fully disable/enable frustum culling at viewer level as an option
Fixes bounding sphere computation
Merge pull request #70 from cedricpinson/bug/bounding-sphere-computation

Fixes bounding sphere computation
Merge pull request #66 from jtorresfabra/frustum_culling

Frustum culling
Updated website to include pagedlod example
[#72032388] Adds occulus helper function inside osgjs
Removes vr.js lib
Merge pull request #72 from cedricpinson/feature/occulus-refactoring_72032388

Feature/occulus refactoring 72032388
Fixed bug in getFrustumPlanes:far plane calculation was assigning wrong the distance value. Also disable culling when the current frameNumber is 0
Merge pull request #73 from jtorresfabra/fix_frustum

Fixed bug in getFrustumPlanes:far plane calculation was assigning wrong ...
Merge pull request #71 from jtorresfabra/update_website

Updated website to include pagedlod example
Adds default template for examples
Disable frsustrum culling by default because of https://github.com/cedricpinson/osgjs/issues/74
Fixes tests
Do not compute near/far frustum clipping planes by default. Fixed bug when clipping childs of MatrixTransform Nodes
Added example composer example with stitching, vignetting and bloom examples

Also included minified dat.gui library in examples/vendor dirs