Indicate dates & versions

[eyalroz]

Hello Martin,

At the moment, the comparison is massively out-of-date - as it seems to refer to doctest when it was less than half its current age, IIANM.

But be that as its may - I believe it is imperative, so as not to confuse people, to do the following:

1. Indicate the release version (or commit hash) used for each column of the comparison table.
2. Indicate the date the comparison was made (which may not be the date of the last editing of README.md)

[martinmoene]

Hi Eyal,

Thanks for the heads-up, you're quite right.

I'm not inclined to invest much work into this at the moment. Perhaps it's nice to keep the comparison for 'historical reasons' and adding a big fat warning to indicate it is ancient is the appropriate thing to do.

[eyalroz]

@martinmoene : Indicating versions and the date of comparison should really not take much time :-(