Created batch file for testing in GHDL for windows

Batch script runs same set of commands as original test_libv
script, but first checks the GHDL version. Script has been
tested using GHDL 0.25 and 0.29, known issue with simulation
under 0.29 (WINDOWS) causes simulation to hang. Script will
warn user if GHDL version is greater than 0.25 and ask if they
wish to continue
Updated test_libv.bat with comments