[ZWeb] canges to default.css please comment

[Robert Rottermann]

I started to clean up deafult.css.

Two things that affect apearance so far:
- changed all links that a:hover-color is the same (kind of orange)
- changed size of links in navigation and news  section.

Explanation:
when using em as units one hase to be very carefull not to introduce
unwanted scaling.
Example from default.css
#SIDE_MENU H1 A {
 font-size: 1.3em;
...
}
here we size a H1 tag by a factor of 1.3. However when a a H1 is used as a
link we size it an other 1.3 times so the overall factor is 1.69.
I think this is not the intended factor and I therefore changed the
stylesheet so that H1 A is scaled the same as H1.

Please comment when these two adaptations run havock with what has been
decided.

Robert