Summary: It is now possible to push the thread status into each critical pair. This leads to higher precision, because when code branches on whether it is on the UI thread, the final abstract state of the procedure will be `AnyThread`, but pairs created in the UI thread branch should know that their status is `UIThread`, not `AnyThread`.
Reviewed By: jvillard
Differential Revision: D18114273
fbshipit-source-id: cbb99b46f
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