In commit 'Create KWSYS_PLATFORM_INFO_TEST macro' (2009-11-20) we
implemented the macro to use a cache entry to avoid re-running the
try_compile(). However, the output copied from the try_compile is
needed on every configure. If the user wipes out the build tree but not
the cache file then the try_compile() will not re-run to recreate the
needed file. We address the problem by teaching the macro to run the
try_compile() whenever its output file does not exist.
This macro helps KWSys perform try-compile tests that extract 'INFO'
strings out of compiled binaries. It works for CMake 2.6 and above.
On CMake 2.4 it always returns an empty list of information values,
so this should be used only as an optimization until 2.6 is required.
This converts the KWSys 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 KWSys copyright to
cover the full development time range.
