Summary:
Change the license of the source code from BSD + PATENTS to MIT.
Change `checkCopyright` to reflect the new license and learn some new file
types.
Generated with:
```
git grep BSD | xargs -n 1 ./scripts/checkCopyright -i
```
Reviewed By: jeremydubreil, mbouaziz, jberdine
Differential Revision: D8071249
fbshipit-source-id: 97ca23a
Summary:
For now: just moving this list behind an abstract type.
Next: changing the internal representation.
Reviewed By: ngorogiannis
Differential Revision: D8140926
fbshipit-source-id: 5b959b0
Josh Berdine
Mehdi Bouaziz
Jules Villard