net bug fix, myextapi now service agnostic

doc/CHANGELOG.md

@@ -96,6 +96,16 @@ Versions follow `MAJOR.MINOR.PATCH-REVISION_STAGE_N` (e.g. `3.99.1-4_rc_1`).
   `setlocale fr_FR` could pick a non-UTF-8 charset; shortcut functions are built
   without evaluating the raw configuration value, and an alias cannot replace
   `setlocale` or `setc`.
+- `myextip`: now uses the HTTPS `https://ipinfo.io/json` API by default, since
+  the free ip-api.com tier is HTTP only (HTTPS answers 403); ipwho.is and the
+  ip-api.com format are still understood, a Timezone line and the postal code
+  are shown, an unexpected answer is reported instead of printing `jq` errors,
+  and a non-HTTPS URL gives a warning.
+- `net.sh`: `dwl` always returned 0 (the cleanup after the transfer masked
+  curl's status), so no caller ever saw a failed download; HTTP errors (404,
+  403, ...) are now failures instead of saved error pages; `urlencode`
+  mis-encoded accents under `LC_ALL` and now uses `%20` for spaces; `isipv4`
+  leaked a variable.
 - `compress.sh`: option flags and loop variables no longer leak into the
   interactive shell.