#59 (Dec 5, 2017, 10:37:45 AM)

1. create material data models (commit: 1293218) (details / githubweb)
2. git add materials models to spar (commit: a4e0466) (details / githubweb)
3. add foam material (commit: 9203eb4) (details / githubweb)
4. fix units error; delete htail override of skin material (commit: 170518e) (details / githubweb)
5. add init file to materials; fix vtail AR (commit: eb4402d) (details / githubweb)
6. make material class attribute of material folder, global variable g (commit: 73f8d76) (details / githubweb)

GitHub pull request #141 of commit 73f8d76ca3d99dd76415aefd542c15d1b70bfcc9, no merge conflicts.