Update the LICENSE file

Now this file will reflect our changes to the use of qthreads, hwloc, re2 and
gmp
Let's call "Knights Corner" 'knc' (and put 'cygwin' in single quotes too), primarily to avoid having to worry about (TM)s, (R)s, etc.  I.e., we're using our identifiers, not their trademarked name (in which case, I think we'd also need to put in "Intel" and a bunch of other stuff too).