Slack 4.1.0

Thanks to a few tweaks to the engine, a polish of the pistons, and recalibrated valves, the app should be running smoother and faster, than before. Spellcheck, revamped, is now a much better version of its old self (and back on Linux, to boot) — now it supports Greek, Portuguese and British English. So now spelling correctly should come more naturally to us all (which is good, because "correctly" can be a difacult word to spell). After uploading a video into Slack some found it would give an infinite circle of loading, but not play, which was never our plan. Now: it works! It plays; no more circle! Because, it turned out, all circ and no play made Slack a null 'ploy.