2.3

This release features a new core for emulating the ZX Spectrum
Another new core is GBHawk (Gameboy and Gameboy Color)

Updated GLideN64 plugin to latest master branch
Updated mGBA core to latest 0.6 branch

Many other core and UI fixes and updates.

See the release notes for more details
http://tasvideos.org/BizHawk/ReleaseHistory.html#Bizhawk23