Release 5.7.8

What's Changed

• Support XDG paths and APIs if available by @trufae in #277
• Fix build with latest r2 from git, use xdg instead of hardcoded paths by @trufae in #278
• Fix Unused pops on _fp_compare (backport)
• R2 5.7.8 by @wargio in #279

Full Changelog: 5.7.6...5.7.8