moved helpers separately

doc/CHANGELOG.md

@@ -22,6 +22,14 @@ Versions follow `MAJOR.MINOR.PATCH-REVISION_STAGE_N` (e.g. `3.99.1-4_rc_1`).
 - `utaz` supports bare `.zst` files and `.tzst` archives; `taz -q` is now
   effective.
 
+### Changed
+
+- Internal helpers are now delivered apart from the modules, in the new
+  `helpers/` directory: `helpers/common.sh` (shared helpers, loaded by
+  `profile.sh` before the modules) and `helpers/<module>.sh` (private helpers
+  of `profile.d/<module>.sh`, loaded by the module itself when the file exists).
+  `_fun_is_uint` became the shared `_is_uint`.
+
 ### Fixed
 
 - `taz`: a plain file with the `tar` format could be deleted instead of being
@@ -174,7 +182,7 @@ Versions follow `MAJOR.MINOR.PATCH-REVISION_STAGE_N` (e.g. `3.99.1-4_rc_1`).
   longer change the shell's directory stack.
 - All modules: the option parsing no longer uses `xargs`, which broke on
   arguments or file names containing a newline, nor `eval`: a new
-  `profile.d/args.sh` provides `_getopt_split` (and `_trap_restore`), pure bash
+  `helpers/common.sh` provides `_getopt_split` (and `_trap_restore`), pure bash
   helpers; the `nullglob` and trap restorations no longer use `eval` either.
 - `profile.sh`: the shell check used `$SHELL` (the login shell: unset under cron
   or systemd, unrelated to the running shell) and made the profile refuse to