broken map error reporting

[dwinslow]

14:56 < dwins> sbenthall: aha. we have some broken map configs in the listing

and really lousy error reporting for the case where a map
configuration is broken

14:57 < sbenthall> dwins: could you make a "Less lousy error reporting on

broken maps" ticket and put it into 0.6? Maybe with
information about what about the map is broken, if you have
it handy?

14:57 < sbenthall> getting a 404 on that url, by the way. not sure what's up

with that

14:57 < dwins> same thing as always, some layer has been renamed and the map

app can't find it

[sbenthall]

Not worth fixing this round because we will be changing the whole map saving/loading setup soon.