[aprssig] Wind distribution graphs

[Steve Dimse]

I haven't gotten a lot of comments about the new wind distribution graph on
wxpage.cgi. After playing with it a bit, the distribution on the length of
history people generally view wxpage seems less than useful. It seems a lot more
interesting on shorter periods. Therefore I've added a second instance on the
page, hardwired at 2 hours. 

In other words, one distribution is for the length of time (generally days)
covered by the other graphs, the second covers the last two hours.

Feedback welcome...

Steve K4HG