BoringSSL.

This is a clone of the repository https://github.google.com/mdsteele/boringssl-bazel at 436432d8 which itself pulls in https://boringssl.googlesource.com/boringssl at 82aa28fa .

The BUILD file is replaced with one containing globs that is more readable.

To update:

1. Save the files README.md and BUILD from third_party/boringssl
2. git clone --recurse-submodules https://github.com/mdsteele/boringssl-bazel
3. Copy the git tree or BoringSSL to third_party/boringssl
4. Remove the WORKSPACE file from third_party/boringssl
5. Copy the saved README.md and BUILD files back