tidy-up: miscellaneous

- INSTALL-CMAKE.md: add missing periods, text fixes.
- md4, md5: sync variables names.
- curl_trc: sync an argument type.
- docs/examples: sync debug/trace function copies, constify, tidy-ups.
- replace commented code with `#if 0`.
- drop redundant parenthesis (macro values, `return`, around single
  variables, function calls).
- fix indentation, apply clang-format in places.

Closes #20481

tests/server/dnsd.c

@@ -632,7 +632,9 @@ static int test_dnsd(int argc, char **argv)
       clear_advisor_read_lock(loglockfile);
     }
 
-    /* logmsg("end of one transfer"); */
+#if 0
+    logmsg("end of one transfer");
+#endif
   }
 
 dnsd_cleanup: