Squashed 'site_scons/' changes from 909e0ee..312e4f1

312e4f1 Don't append library version to shared libraries on Darwin

git-subtree-dir: site_scons
git-subtree-split: 312e4f12e60cb85053b03fddfe8cc2f3058d66b9
Merge commit 'df5be929a54ea05fe6264ee4fc35ae7cf5391085'