M3U updates, Maintenance

Created by: sonninnos

M3U:

• Added ability to specify a file inside a ZIP: <disks>.zip#<disk>.adf

Minor:

• Core option label touch-up
• Disable turbofire automatically with mice
• VKBD numpad color fix

Other:

• Libretro file maintenance (removed retro_strings & retro_files)
• Readme updates
• Tabs to spaces