Added default css behaviour

Added bbox-sizing: border-box so that sizes of objects include the
margin and padding and borders as well. Also added default margin
and padding values of zero. So I also increased the default size of
the map and the flags.
Bugfix with event handling in menus
Removed top_padding element

Now I use a margin-top on the body-element instead.
Fixed css and related stuff for the menu

Now looks a bit better.
Compressed the map using svgo-gui for windows
Put the a3to2 variable on one line