[CMake] ctest, make test and build config

[ross hennessy]

> I'm then calling ADD_TEST as follows -
>
> ADD_TEST(${TESTNAME} "${CMAKE_COMMAND}" -D
> WORKING_DIR=\${CMAKE_CFG_INTDIR} -P
> ${CMAKE_CURRENT_BINARY_DIR}/${TESTNAME}.cmake)

I forgot to mention that with CMAKE_CFG_INTDIR I also tried removing
the \ which was escaping the $ so that CMAKE_CFG_INTDIR was evaluated
at cmake time to $(OutDir), but then this didn't seem to get set by
VisualStudio when building the RUN_TESTS target either.

Thanks, Ross