Handle non-ascii correctly

[Peter]

First of all, lovely plugin!

This works:

{{{
#!graphviz

digraph Works {

  Stockholm [label="Stockholm stad" ]
  Örebro [color=red, label="Örebro stad"]

  Stockholm->Örebro

}
}}}

Adding URL="whatever" fails with message:

Genshi UnicodeDecodeError error while rendering template (unknown template location)

{{{
#!graphviz

digraph Fails {

  Stockholm [label="Stockholm stad" ]
  Örebro [color=red, label="Örebro stad", URL="whatever"]

  Stockholm->Örebro

}
}}}

If this is a config error please hint in docs.

[anonymous]

This seems also to break the TracTicketDepgraphPlugin

See here for a simple patch to solve that problem ​http://trac-hacks.org/ticket/8566#comment:4