CLOG: add support for substring matching.

So that `--log "*undo*"` matches any log identifier containing `undo`.

Reviewed By: campbellbarton

Differential Revision: https://developer.blender.org/D10647

source/creator/creator_args.c

@@ -869,6 +869,8 @@ static const char arg_handle_log_set_doc[] =
     "\tEnable logging categories, taking a single comma separated argument.\n"
     "\tMultiple categories can be matched using a '.*' suffix,\n"
     "\tso '--log \"wm.*\"' logs every kind of window-manager message.\n"
+    "\tSub-string can be matched using a '*' prefix and suffix,\n"
+    "\tso '--log \"*undo*\"' logs every kind of undo-related message.\n"
     "\tUse \"^\" prefix to ignore, so '--log \"*,^wm.operator.*\"' logs all except for "
     "'wm.operators.*'\n"
     "\tUse \"*\" to log everything.";