MapTool 188.8.131.52 is available for download from http://www.rptools.net/ by clicking on the Download link in the top toolbar.
The commit log is available via the GitHub page but many of the changes were related to the build system and automation; I’ve tried to separate them in the spoiler area, below, but no guarantees. (MapTool 184.108.40.206 was released Jul 2nd, 2016 so commit entries prior to that apply to the previous build.)
Major fixes include the token ID bug (where tokens contain all digits and are converted to numbers) and a problem with Meta-I not clearing FoW properly (Ctrl-I on Windows and Unix, Cmd-I on macOS).
You can find a full list of changes on the forums.