sends parameter info in a list for use in dartdoc
sends parameter info in a list for use in dartdoc

for example, the dartdoc for Stream.listen would have now the extra key

```
  "parameters": [
   "(MouseEvent) → void onData",
   "{Function onError}",
   "{() → void onDone}",
   "{bool cancelOnError}"
  ]
  ```

kasperpeulen/dart-services,kasperpeulen/dart-services,dart-lang/dart-services,kasperpeulen/dart-services,dart-lang/dart-services,dart-lang/dart-services