Lightgun support and new firmware fixes

Rerelease due to lightgun not being properly disabled. Sorry about that

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Thanks to @iequalshane to adding lightgun support for this release! Turn on one of the lightgun options in Core Settings, and you can control the onscreen lightgun cursor with the D-Pad or using an analog stick from an external controller.

Includes several other bug fixes, and re-enables some previously disabled features due to the latest Analogue firmware update fixing some things.

Changelog

• fix (#29): Enable reading SRM save files
• fix (#28): Properly set RAM size for ST010 chip
• fix (agg23/openfpga-NES#3): Ignore ROM header and calculate ROM size manually
• fix: Properly constrained audio clocks
• feat: Added 4:3 video setting
• feat: Virtual Super Scope and Justifier lightgun support. (#32)
• fix (#33): Added reset option and ROM swapping
• fix: Fixed lightgun always being enabled