Merge pull request #149 from KeyMaster-/master

Added function to set blend equation
Vector; Quaternion; Matrix; make int based enum for order instead of string
::MINOR API CHANGE:: Maths; utils weighted_average -> weighted_avg
Samples; alpha; push first alpha sample demo code prepping for blog post
Vector; fix misnaming of weighted_avg from utils. This has changed in a coming branch so in preparation will just be patched internally to allow builds to succeed again