Fixed problem which prevented to load selected memory cards when starting...

 Fixed problem which prevented to load selected memory cards when starting core without content (#161)

* - BIOS in game config now is stored by name instead of full path, making it more portable

* - added check if bios folder is empty, logging in that case an explicit message

* fixed problem wich prevented to load selected memory cards when starting core without content

* removed a forgotten debug log
2 jobs for main in 4 minutes and 22 seconds (queued for 2 minutes and 49 seconds)
Status Name Job ID Coverage
  Build Shared
passed libretro-build-linux-x64 #876611

00:02:33

passed libretro-build-windows-x64 #876610
msvc2019

00:01:48