config: pass kvi to die_bad_number()

Plumb "struct key_value_info" through all code paths that end in
die_bad_number(), which lets us remove the helper functions that read
analogous values from "struct config_reader". As a result, nothing reads
config_reader.config_kvi any more, so remove that too.

In config.c, this requires changing the signature of
git_configset_get_value() to 'return' "kvi" in an out parameter so that
git_configset_get_<type>() can pass it to git_config_<type>(). Only
numeric types will use "kvi", so for non-numeric types (e.g.
git_configset_get_string()), pass NULL to indicate that the out
parameter isn't needed.

Outside of config.c, config callbacks now need to pass "ctx->kvi" to any
of the git_config_<type>() functions that parse a config string into a
number type. Included is a .cocci patch to make that refactor.

The only exceptional case is builtin/config.c, where git_config_<type>()
is called outside of a config callback (namely, on user-provided input),
so config source information has never been available. In this case,
die_bad_number() defaults to a generic, but perfectly descriptive
message. Let's provide a safe, non-NULL for "kvi" anyway, but make sure
not to change the message.

Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/submodule--helper.c

@@ -2192,13 +2192,13 @@ static int update_clone_task_finished(int result,
 }
 
 static int git_update_clone_config(const char *var, const char *value,
-				   const struct config_context *ctx UNUSED,
+				   const struct config_context *ctx,
 				   void *cb)
 {
 	int *max_jobs = cb;
 
 	if (!strcmp(var, "submodule.fetchjobs"))
-		*max_jobs = parse_submodule_fetchjobs(var, value);
+		*max_jobs = parse_submodule_fetchjobs(var, value, ctx->kvi);
 	return 0;
 }