binlog protocol

see #78 

Currently only implemented RotateEvent, FormatDescriptionEvent and QueryEvent.

output of `examples/binlog-watcher.js` example while `create database testtest1` and `drop database testtest1` executed on server:

```
{
  slaveProxyId: 3,
  executionTime: 0,
  errorCode: 0,
  schema: 'testtest1',
  statusVars:
   [ [ 0, 0 ],
     [ 1, 1075838976 ],
     [ 6, 'std' ],
     [ 4, [Object] ],
     [ 12, [Object] ] ],
  query: 'create database testtest1',
  name: 'QueryEvent',
  header:
   { timestamp: 1393140952,
     eventType: 2,
     serverId: 1,
     eventSize: 105,
     logPos: 647,
     flags: 8 } }
{ slaveProxyId: 3,
  executionTime: 0,
  errorCode: 0,
  schema: 'testtest1',
  statusVars: [ [ 0, 0 ], [ 1, 1075838976 ], [ 6, 'std' ], [ 4, [Object] ] ],
  query: 'drop database testtest1',
  name: 'QueryEvent',
  header:
   { timestamp: 1393140966,
     eventType: 2,
     serverId: 1,
     eventSize: 91,
     logPos: 738,
     flags: 8 } }
```