[phenixbb] Map filenames are not honored [dev-610]

Hi, I just noticed that v610 does not honor map file names defined in the .def file. Instead it constructs its own file name from the prefix, serial and map_type settings. That works fine for run-of-the-mill fofc and 2fofc maps, but causes a clash in map filenames when one also computes kicked maps or other maps with non-default settings beside the default fofc and 2fofc maps. Cheers, Carsten