Aleph One 1.7b1

This is a beta release to help test a few new features for end users coming in 1.7:

• Optional 3D positional audio using OpenAL soft, including HRTF
• Support for map-specific resources plugins. See https://simplici7y.com/items/m2se-music-plugin/ for an example
• HUD plugins are now selectable from graphics preferences as well as plugins, for more discoverability

As well as these features for mappers:

• New music API for Lua which allows multiple tracks and crossfades
• New transfer modes for reverse horizontal / vertical slide
• New transfer modes for 2x / 4x tile transfer
• New MML for larger tiling for replacement textures
• Additional fog options in MML/Lua