This adds copyright/license notification blocks CMake's find-modules.
Many of the modules had no notices at all. Some had notices referring
to the BSD license already. This commit normalizes existing notices and
adds missing notices.
CMAKE_MINIMUM_REQUIRED(VERSION), because the cmake they are shipped with is
always ok. Additionally, if a Find-module does CMAKE_MINIMUM_REQUIRED(), it
changes the policies as they may be set up by the project. So this shouldn't
be done in a Find-module (or surrounded by policy-push/pop commands)
Alex
Alex Neundorf
Todd Gamblin
Brad King
Philip Lowman
Christopher Harvey