MINOR: pattern/map/acl: Centralization of the file parsers

The acl and map function do the same work with the file parsing. This
patch merge these code in only one.

Note that the function map_read_entries_from_file() in the file "map.c"
is moved to the the function pat_ref_read_from_file_smp() in the file
"pattern.c". The code of this function is not modified, only the the
name and the arguments order has changed.
diff --git a/src/acl.c b/src/acl.c
index b4bb536..5576187 100644
--- a/src/acl.c
+++ b/src/acl.c
@@ -451,7 +451,7 @@
 			snprintf(trash.str, trash.size, "acl(s) loaded from file '%s'", args[1]);
 			trash.str[trash.size - 1] = '\0';
 
-			if (!pattern_read_from_file(&expr->pat, PAT_REF_ACL, args[1], patflags | PAT_F_FROM_FILE, err, trash.str))
+			if (!pattern_read_from_file(&expr->pat, PAT_REF_ACL, args[1], patflags | PAT_F_FROM_FILE, 0, err, trash.str))
 				goto out_free_expr;
 			is_loaded = 1;
 			args++;