Pancake-free Woolly Mammoth Skeleton

After waking up to some pancakes on my print-bed when printing the Stegosaurus bases, I traced back the issue to the model. Now, I am repairing all of the dinosaur models here.

I've repaired the parts so that they can print properly now without making any more surprise pancakes.

Fixes:
-Fixed normals
-Closed solids
-Removed Self Intersections
-Made manifold
Some of the models required multiple passes to be completely free of errors. Rechecked in Windows 3D Builder just to be sure.