css-justifying some content

[kaputtnik]

The attached patch do some visual corrections to the wiki:

 - Tablecontent gets a little space to make them not stick together
 - Header paddings adjusted: above is more space than below
 - Because of the mighter space above headings, the first Header will become far away from the top of background. This is fixed for headers level1 and level2.
 - Add a little space after the tables to prevend that text sticks at the table. See https://wl.widelands.org/wiki/EditorHelpHelp/ for another example how it looks today

Correction for the Forum:

 - the top border of the donatebox (right side) isn't equal to the top border of the topic-section (left side) . This would be also fixed.

See https://wl.widelands.org/forum/topic/1611/ for Screenshots.

[SirVer (sirver)]

Thanks. Applied in r379.

[kaputtnik (franku)]

Thanks

A nice christmas gift :-)