Can all be ignored - it's because we had to have these intermediate updates for technical reasons, but internally the code is just Corona 13, ie we've been working as normal where there was Corona 12 in November last year, and Corona 13 in June this year. For the required Update 1 and Update 2 that are not part of the usual release cycle, we just branched those off when it came time to release them.
And that is all over now, so just ignore it :) Things are back to business as usual!