Refactor how cmCTestMemCheckHandler computes the memory tester command
line options to avoid encoding them in a single string just to parse
them again. The EscapeSpaces uses backslahes to escape spaces on UNIX
platforms, so replace other calls to it in CTest that are used to create
human-readable strings with simple double-quoting.
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.
