Include date a charm was published on charm page

[mthaddon]

It would be very useful to include the date a charm was published on the charm page.

Currently it's very hard to know from looking at the charm page what version of code it was built from. This isn't easily solvable due to the charm build process which removes version control information, but if the date a charm was published was displayed, you'd know that it couldn't include code committed to the project that it's built from after that date.

[frankban]

We don't have that information available from the charm store yet, but we a medium-term task in the direction of polishing the whole publishing process, and this is a valid point that should go into that story.