Comma is missing among the binary selector characters

[mkobetic]

I fixed the same issue in STIG recently (Xtreams define a comma method), but I'm still wrapping my head around the tools on the squeak/pharo side. So just an issue report atm. I checked the actual list of permitted characters for binary selectors and comma should be the only one missing

[mkobetic]

The fix is simple, just needs adding something like `at: $, put: 'comma';' to #initializeSpecials