Merge branch 'clarify-which-bsd' into 'master'

LICENSE: Clarify which BSD license is being used

See merge request !174

LICENSE

-All files in this development are distributed under the terms of the BSD
-license, included below.
+All files in this development are distributed under the terms of the 3-clause
+BSD license (https://opensource.org/licenses/BSD-3-Clause), included below.
 
 Copyright: std++ developers and contributors