Merge pull request #1 from kezhuw/master

some fixes
remove debug printf
simple rpc support
service client and a simple DB example
bugfix: use negative session id for request message
We don't need hash map in gate
try more when writev return EINTR
bugfix: client send
connection server
bugfix: read block
readme layout
stand alone skynet without skynet-master
use big-endian for client package
broker & launcher
bugfix: when init module failed, release message queue
lua serialize support
simple redis
change source dir
fix typo in README
add some lua library