RSS should use Group Timestamps

[jidanni]

Before I start trying all the methods mentioned in the thread
"Re: How to speed up the nnrss rechieving? Too slow!",
I would just like to point out that maybe gnus could start using
the precise-down-to-one-second Group Timestamps,
 (info "(gnus)Group Timestamp") <- `C-x C-e' here,
to keep track of how often the user would like each RSS group checked
for new items.

E.g., Billy likes Nerdsgroup checked every 60*60*8.5 seconds, whilst
Teurdsgroup he sets for once every two days.
And he can do this all say in .gnus.el or some other file he can use an
editor on, and not some customize of group parameter special
interface.

If the time has not arrived to check again, the group is not updated,
with no need to tinker with whatever group levels jazz. Of course
hitting a C-u something with the cursor on top of a RSS group would
refresh it right now.

The gnus-group-line-format could have a new % escape, that could
display the value Billy set for each group.

So please somebody enhance nnrss.el or whatever to use Group Timestamp
capabilities real soon now.