Reduce timestamp specificity on profile
Reduce timestamp specificity on profile

Problem: Concern has been expressed about being able to see granular
timestamps on the profile page, which would let you see "active 3
seconds ago" or similar. This is public metadata that anyone can access,
and we **can not** provide privacy with UI decisions, but the idea that
high specificity in the UI is creepy seems fair to me.

Solution: Change the display format so that the options are "Today",
"Yesterday", "Last $weekday", or the default date formate for the locale
in question. Since we aren't hardcoding strings, this should continue to
be localized.

ssbc/patchwork,ssbc/patchwork