Apothecary assimp formula update for 64bit / libc++ 

This commit shows the formula changes.
https://github.com/openframeworks/openFrameworks/commit/270075c5c145c5534bd58fb728e0a579640b8730

The other commits are the changes needed to OF for the new assimp API. 

One small issue I noticed is the astro boy model is coming in 100 times smaller with this version of assimp. 
The 4 other models in the example load fine, but for some reason astroboy ( collada )  needs to be scaled by 100.0. 

Feel free to send PRs against this branch for nix/win android etc. 
Ping @arturoc 

I will work on the iOS formulas next.