refactor(error): improve default error handler

Show date, pid, child class name, error addition property.
e.g.:

```log
[Thu Nov 06 2014 11:28:50 GMT+0800 (CST)] ERROR 64170 [sdk-base] Unhandle SomeServiceClientError: mock error 1, stack:
Error: mock error 1
    at null._onTimeout (/Users/mk2/git/sdk-base/test/index.test.js:34:19)
    at Timer.listOnTimeout (timers.js:133:15)
{ [SomeServiceClientError: mock error 1]
  data: { foo: 'bar', url: '/foo' },
  name: 'SomeServiceClientError' }
```
Merge pull request #2 from node-modules/improve-default-error-handler

refactor(error): improve default error handler