+20191221
+ + correct pathname used in Ada95 sample programs for explain.txt, to
+ work with test-packages.
+ + improve tracemunch:
+ + keep track of TERMINAL* values
+ + if tracing was first turned on after initialization, attempt to
+ show distinct screen, window and terminal names anyway.
+ + ensure that GCC_NORETURN is defined in term.h, because the prototype
+ for exit_terminfo() uses it (report by Werner Fink).
+