backtrace-libbt 1.18.1

This release improves propagation of heuristic indicators to child frames and propagated custom custom map paths to debug links.

Features and Improvements

• Heuristics have also been added to exclude the primary executable image from
  --map-path (instead, relying on the root filesystem), for convenience
  purposes.
• The guessed heuristic is now applied to all child frames, including inline
  frames.

Bug Fixes

• The --map-path option (similar to sysroot with GDB), will now apply the user-provided path to debug information files.
• Fixes an issue in the libbt tool where null frames were omitted.