set_property() has APPEND, which creates a list. E.g. when
appending to COMPILE_FLAGS a string is needed, not a list.
With the APPEND_STRING option the value is append as string,
not as list.
Alex
This converts the CMake license to a pure 3-clause OSI-approved BSD
License. We drop the previous license clause requiring modified
versions to be plainly marked. We also update the CMake copyright to
cover the full development time range.
Stephen Kelly
Ben Boeckel
Alex Neundorf
Brad King
Ken Martin