Resolve a few more bugs

This version fixes some weird cases where things converged but did not converge. It turns out that I was throwing away the correct solution just before printing the result.

v3.14.1 (30 Jan 2024)

• no longer toss correct solution in some cases
• only calculate redistribution matrix when needed
• improve debug comments
• start stripping tabs from cweb files
• minor changes to text in output file

v3.14.0 (25 Jan 2024)

• fix handling of slides (@anishabahl)
• fix github build
• improve Makefile
• warn on bad sphere wall reflectivity