Loading files with metadata

[Timendus]

Work in progress:

• Adds preliminary support for CBF
  • Metadata read from file, program just runs, no settings overlay
• Adds fairly complete support for the CHIP-8 database
  • The settings overlay now shows program & ROM metadata
    • Title
    • Authors
    • Release dates
    • Embedded titles
    • Descriptions
    • Links
    • Key mappings
  • It also allows changing the key mappings, both for keyboard and for gamepad input
• Allows multiple notifications to show at the same time

TODO

• [ ] Do some proper testing
• [ ] Add support for configurable colours, maybe?
• [ ] Show CBF metadata in the setting overlay too
• [ ] Fix tests