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.
This creates an undocumented 'ctest --launch' mode. It launches a
specified command and optionally records a failure in an xml fragment.
We will optionally use this in CTest's Build stage to record per-rule
build failure information when using Makefile generators.
