Mention hiding internal symbols in the changelog
rather than one large chunk. This simplifies accessing memory in
`MMDB_get_entry_data_list()` and increases performance. It builds on the
changes in 1.3.0 and 1.3.1.
+* We no longer export `data_pool_*` symbols. These are internal functions
+ but we were previously exporting them. Pull request by Faidon Liambotis.
+ GitHub #162.
## 1.3.1 - 2017-11-24
