fixed unicode serialisation

[toyg]

trafficstars

unicode characters in arguments get mangled up. Tested in Python 3.3.3 only.

[toyg]

Works fine in 2.5+ as well. Should be safe to merge :)

[thedod]

I was just about to pull request the same: 666d96a2cea :laughing:. Anyway, :+1:

[luke-jr]

Hmm, this doesn't seem to actually fix the issue, just avoids the infinite loop. In particular, by casting to a float you're not ensuring the Decimal value gets encoded correctly (with 8 decimal places). I think fixing this properly will require subclassing JSONEncoder - no need to round the value, though, just get it included precisely.