PDCurses 4.3.4

(See docs/HISTORY.md for more details, and/or the Git log for extreme detail.)

• Files created by getwin() and putwin() should now be usable between future versions of PDCursesMod, across most OSes and compilers, and (with limitations) even between wide/narrow and 32-bit/64-bit chtype builds.
• endwin() was not signal-safe. (Memory was freed and buffered file output was done; both are signal-unsafe.) See 'upstream' issue wmcbrine/PDCurses#134 for details.
• We now use wcwidth(), instead of our own internal version, on Linux. This avoids some redundancy and may enable better results in non-Unicode environments, if any.
• Also updated our PDC_wcwidth() from Unicode 5.0 to Unicode 14.0.0.
• WinGUI could block if there was no key delay.
• Alternative character set glyphs were sometimes shown when they ought not to be, or vice versa.
• You can free all remaining internal memory with the new PDC_free_memory_allocations() function. This is not strictly necessary, since all memory is freed on exit anyway. But it can help when using Valgrind or similar memory diagnostic tools; you can eliminate any possible PDCursesMod leaks.
• Lots of small bug fixes and improvements... again, see docs/HISTORY.md for more details.