Use caf to compile tests and cafrun to run them

 - Fixes #275
 - No longer need to keep track of failed images test via properties since
   --disable-auto-cleanup is passed by default by cafrun unless explicitly
   disabled, when ULFM/Failed image support is detected.
 - For simpler tests/executables pass source files/object files to CMake
   function `caf_compile_executable` defined in top level CMakeLists.txt
 - For complex tests/executables set `CMAKE_Fortran_COMPILER` to `bin/caf`
   and make sure to add a dependency on the OpenCoarrays library (static)
   for any targets built with this method. (See the coarray Burgers PDE
   integration test's `CMakeLists.txt` for an example.)
 - Ensure that proper Fortran flags get sent to the `caf_compile_executable`
   funciton, which is non trivial because it depends on the `CMAKE_BUILD_TYPE`
   and some use mixed case, whereas the variables storing the flags are all
   caps
 - Ensure defines/macros passed correctly

Author: zbeekman