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.
Previously we stored a vector of tests to preserve their order.
Property set/get operations would do a linear search for matching tests.
This uses a map to efficiently look up tests while keeping the original
order with a vector for test file generation.