Move oidset_parse_file() to oidset.c

Signed-off-by: Barret Rhoden <brho@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

oidset.h

@@ -73,6 +73,14 @@ int oidset_remove(struct oidset *set, const struct object_id *oid);
  */
 void oidset_clear(struct oidset *set);
 
+/**
+ * Add the contents of the file 'path' to an initialized oidset.  Each line is
+ * an unabbreviated object name.  Comments begin with '#', and trailing comments
+ * are allowed.  Leading whitespace and empty or white-space only lines are
+ * ignored.
+ */
+void oidset_parse_file(struct oidset *set, const char *path);
+
 struct oidset_iter {
 	kh_oid_t *set;
 	khiter_t iter;