Clean Code: 1. Just use THIS_MODULE to put_module. 2. Rename module open name as /dev/fastsocket
Fix Bug: 1. Release resouces correctly  when new socket failed. 2. Clean fastsocket_xxx code
Fix Bug: 1. In function fsock_alloc_file, When allocate file failed, just free dcache and not interact socket clean up outside
Fix Bug: 1. In fucntion fsocket_accept, free socket when allocate new file failed
Fix Bug: 1. Add gcc -g flags to compile so
Fix Bug: 1. Check whether target socket is a listen socket when doing listen spawn
Fix Bug: 1. Dynamically expands fastsocket fd set when it's reaching the current max set size
Add Function: 1. Add accept failed proc statistics
Clean Code: 1. When epoll_ctl, no need to do epi lookup particularly for listen socket, since we already dup a listen file when listen spawn. 2. Clean epoll_ctl code
Add Function: 1. Add a switch to enable or disable Fastsocket-Epoll.
Clean Code: 1. Make RFD code look better.