[Tilesathome] Check font rendering

[Stephan Knauss]

Knut Arne Bjørndal wrote:
> The map is supposed to be rendered with dejavu, if a renderer doesn't
> have that installed it's broken.

Knut, are you aware that DejaVu does not contain all needed characters? 
The renderer has to fall back to another font.

That's why I state that we need to specify the font more precisely.

http://dejavu.svn.sourceforge.net/viewvc/dejavu/trunk/dejavu-fonts/langcover.txt

Mapnik does a fallback to unifont:
<FontSet name="DejaVu Sans Book">
<Font face_name="DejaVu Sans Book" />
<Font face_name="unifont Medium" />
</FontSet>


Stephan