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.
- The find_* commands now provide a HINTS option.
- The option specifies paths to be preferred over the system paths.
- Many Find* modules were using two find calls with NO_DEFAULT_PATH
to approximate the behavior, but that blocked users from overriding
things with CMAKE_PREFIX_PATH.
- This commit uses the HINTS feature to get desired behavior in
only one find command call.
Todd Gamblin
Brad King
Bill Hoffman