Currently pacman stores build and install dates as a textual string. This not only bad for localization, but bad if we ever want to do any calculations / sorting based on dates. These should instead be stored as a numeric time_t. This will allow us to easily output localized time.

The complexity comes up when thinking about how to do this while still maintaining the old scheme... perhaps a check to see if the first char is a number or not and use that to decide which scheme to use?

This is non critical, but a nice-to-have (and fairly simple to fix)