Initial version that actualy create thumbs

The following request creates 2 thumbs:

```
curl -d '{"SrcImage": "file:///home/yml/image1.jpg",
"Opts": [{"Width":250, "Height":0}, {"Width":50, "Height":50}],
"DstFolder":"file:///home/yml/thumbs/"}'
'http://127.0.0.1:4151/put?topic=test'
```