Removed the normal generation from the Renderer. There are
situations where it's perfectly reasonable to desire a mesh
with no normals, and thus loading one without adding them if
they're not there should be supported. This also decreased load
time for meshes without normals and makes them render correctly.
Changed the Texture class to take a renderer instance rather than
a raw webgl rendering context to support use of extensions.

Implemented Extension class to encapsulate use of extensions.

Implemented support for anisotropic filtering.

Adjusted all plugins that create new Texture instances to fit.
Removed the texture instancing plugin and the TextureSampler class.
Removed instances from texture icon.
Built icon files.
Removed the Color class from the renderer, and replaced all colors
in core and the plugins to use vec4's and all vectors to use
vec3's.
More data type cleanup in the renderer.
Renderer: Rewrote scene bounding box storage logic.
Renderer: Changed scene load to be async.
Upgraded msg(...) to support WARNINGS as well as ERRORS.
Upgraded msg(...) to support the 'INFO: ' tag as well as
WARNINGs and ERRORs. Used pale blue. Converted a number
of renderer ourput to INFO.
Moved ExpandableTextField from ui.js to util.js.
Removed scripts/ui.js
Added new plugins for setting texture min/mag filtering and
texture s/t UV-coordinate wrapping mode. Added icons.
Moved the VR initialization code out of the markup and into
core.js where it belongs.
remove unused jsdom from package.json
Updated the frame dump server to create the output directory if
it doesn't exist, and to do so in the project root so it is
separated per-project.
Style changes from Antti. Now we just have to unbreak it a bit.
Frame dump: Server / client - don't reallocate objects unless
required.
Change the client side to send RGB data reducing the amount of
data OTW with 25% and memory likewise.

Server: Remove flipImage logic, replaced node-png with homebrew
TGA 'encoder', which does not reallocate unless the resolution
changes. This is much faster. In the test-case frame times
dropped from 300-400ms down to <10ms and memory use is now low,
not to mention constant.