add Vec2 impls for into-buffer proto method, add 2d overlay shader & helper fns
add 2d overlay of light depth texture to demo
overdue update to polygon PTessellate impl, returning only raw face vectors
regression fixes in tetrahedron ns, update isec fn references & area impl
migrate into-buffer to new protocol PIntoBuffer, add stride arg, update impls, add Polygon2 support for  PWebGLConvert, add fill-buffer-vec3 fn
refactor as-webgl-buffer-spec impls to produce map directly usable by make-attribute-buffers-in-spec, also add color buffer generation option, add ortho projection matrix ctor based on current view rect
add basic color shader gen (mainly for 2D, but 3D supported too), add phong draw gn, update uniform setters to support single boolean vals
add & refactor demos (add 2d polygon example & 3d version w/ phong shading)
add stats.js (in /babel/resources) and update html template
add BasicMesh type, add empty method to PGeomContainer, update references

migrate into-mesh, map-faces (renamed to map-mesh) to types.utils ns
add transform-mesh fn in types.utils
add total-area-3d & total-volume to core.utils
add PWebGLConvert impl for BasicMesh type, update examples to use BasicMesh instead of GMesh
add BasicMesh type (missing from a prev commit)
minor: add notes to subdivision ns