Run server with child process.

You can run server with child process.
You can specify some server options.
Here is options
1  -l [number] you can specify [number] how many lines to send message for client
2  -p You can send server message in child process which is spawned in server
I got bellow error in my environment, if I run server to write data in child process file descriptor.
Here is instructions and out put
./server  1234 -l 256 -p & ./client 127.0.0.1 1234
Here is output
   0 I got the connection
   1 I got the connection
   2 I got the connection
   3 I got the connection
   4 I goError reading from socket:Function not implemented


@dscho Would you mean that I work for above extension, not yourself? If you didn't, I will cancel this pull request.