Edited em_install_GnGeoPi() to not compile if source isn't updated.
Updated rps_main_options to delete directory emulators/gngeo-pi-0.85 before running em_install_GnGeoPi
Added em_install_GnGeoPi() to function rps_update_emulators()
Changed em_install_mame4allpi() to not compile if source isn't updated
Changed rps_main_options() to delete directory ~/RetroPie/emulators/mame4all-pi before running em_install_mame4allpi()
Added em_install_mame4allpi() to rps_update_emulators()