minor css changes
minor css changes

replaced min-height with margin-bottom as
there is better browser support (eg. this works in IE)
SiteIcon / svg icon for a tiddler now has a set height of 25px
padding makes it look nicer.

TiddlySpace/tiddlyspace,FND/tiddlyspace,FND/tiddlyspace,TiddlySpace/tiddlyspace,TiddlySpace/tiddlyspace,FND/tiddlyspace