Merge pull request #144 from cloudwu/dev

pre release 0.5.0
release 0.5.0
remove unused skynet_context_init
add sharedata
bugfix: update until delete
fix typo
remove debug print
add skynet.response for delay response
add response test mode
bugfix: socket.read(fd, nil) should clear buffer size to 0
Merge branch 'master' into dev
remove register_slave
Merge pull request #1 from cloudwu/dev

Dev