Licensing clarification

[charl]

Can you please clarify if the BSD license you are referring to in the README.md is the 4-,3- or 2-clause BSD license?

The latter two (2/3-clause) are GPL-compatible and vetted as OSS licenses. The former (4-clause) is not.

[nemith]

The license in README.md only had two clauses which match up to the FreeBSD Simplified BSD or 2-clause license.

I added a explicit LICENSE file in 60e9d49 with this same license repeated for clarity.