Add Modern Masters sets to "show set release dates", and use correct codes for that overlay.
Add Modern Masters (MMA) and Modern Masters 2015 (MM2) to the "show set release dates" overlay. Also, the Theros (THS), Born of the Gods (BNG), and Journy Into Nyx (JOU) set codes are currently not correct on that overlay.
Ok, I have those set codes fixed now, along with a couple others. Please let me know if you find any others that are incorrect, if you would please.
As for the Modern Masters sets, I believe all we are adding is core sets, and sets within each respective block. That's something I'll have to try and check about to be sure, though. Again though, if you find any other errors besides that, please let me know and I'll get it fixed.