Original commit message from CVS:
* plugins/indexers/gstfileindex.c: (_file_index_id_free),
(gst_file_index_load), (gst_file_index_add_id),
(gst_file_index_get_assoc_entry):
* plugins/indexers/gstmemindex.c: (gst_mem_index_free_format),
(gst_mem_index_free_id), (gst_mem_index_add_id),
(gst_mem_index_index_format):
Use GSlice when possible.