Subclasses of of Exception should be named *Exception

[kevmoo]

Short list (there may be more)

lib/api/errors.dart:class AppEngineError implements Exception {
lib/api/errors.dart:class NetworkError extends AppEngineError implements IOException {
lib/api/errors.dart:class ProtocolError extends AppEngineError implements IOException {
lib/src/protobuf_api/rpc/rpc_service.dart:class RpcApplicationError implements Exception {