Merge pull request #43 from potree/develop

Develop
using plas.io's laslaz.js to handle las and laz octrees
added some materials, general improvements
fixed bounding box handling
fiddling around
minor stuff
.
some progress on large coordinate support and support for las, laz and binary
.
added las and laz examples
merging
fixed examples
fixed merging issues
Changed Float32Attribute to BufferAttribute

 Float32Attribute is deprecated
Changed position copying from = to copy()

spStart.position = I.point; -> spStart.position.copy(I.point);
spEnd.position = I.point; -> spEnd.position.copy(I.point);
made build
added classification material
fixed 'toOrigin' option for large coordinates
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removed unnecessary code