fix node helper
Merge branch 'master' into dev
fix NaN in mat3.scale

This closes #68.
test coverage for vec3.transformMat4
vec3.transformMat3
quat.rotationTo
oops, forgot to document quat.rotationTo
note that both vecs should be unit length
unit tests for mat3.fromQuat
fix quat.fromMat3 sometimes produces reverse of expected result

when fTrace > 0.0, m was treated as the transpose of m, causing
specs to fail.
quat.setAxes
clarify documentation for quat.fromMat3
Clarified vec_.subtract documentation

Co-worker pointed out that the documentation was ambigious about the
order the arguments were used in
mat3.fromMat2d documentation fix

Fixes #69
Added vec_.scaleAndAdd

I've found this to be particularly useful for timing-dependent code,
such as applying velocity to a vector
Fixed viewport scaling of docs pages on mobile
fix documentation

Closes #70.
Merge branch 'dev' of github.com:toji/gl-matrix into dev
code coverage for quat.rotateX, quat.rotateY, quat.rotateZ
faster implementation of quat.slerp