Revised header layout

After trying this on the start page, with no adverse comment - I've applied the change to all pages now.
The main difference is a larger latest temperature and report line.
I noticed the small text is not easy to read on smaller devices such as tablets without zooming.
There is also subtle change to the date layout.

While doing that, a clock and (this) Blog link is now also included on all pages.
Initially somewhat experimental I have found it a useful add on as much for my own use as anything but I notice a gradual increase in traffic with several regular visitors.