split FPI into 2 variants

which gives the user more freedom of choice.
use preprocessor macro to determine the class name
adding test models with different EWSB solvers selected
correcting used EWSB solver (copy-and-paste error)
put run_cmd() into separate header for reuse
set used benchmark model to CMSSM
adding comparison of EWSB solvers
put run_cmd into the test library
do not exit test if child exited with non-zero error code
fixing indentation and define boost macro to avoid early exit