With the Makefile generators we expect that touching or modifying the
input file of a configure_file, or removing its output, will cause CMake
to re-run on the next build. Extend the RunCMake.configure_file test
with a case covering this. Also check that CMake does not re-run if
nothing has changed.
Extend the RunCMake.configure_file test with a case covering possible
common typos of the COPYONLY option.
Reported-by: Iosif Neitzke <iosif.neitzke@gmail.com>