You can get any of the recent (or older) builds on the Source Code tab above.
The latest build version is 22.214.171.124. Version 126.96.36.199 is
here. Once there, you can click the 'Download' link.
These builds on the Source Code tab do not include the compiled DLL for the BIN folder. If you have Visual Studio (express version is free), you can compile the BE core project which will produce a DLL to put in your BIN folder.
Sometimes changes are made outside the BE core, where you can just edit those files without needing to recompile. But these particular fixes related to new comment email notifications were changes made in the BE core -- so a recompile is necessary.