Add example hiredis adapter for muduo
Update hiredis example

remove the C style hiredis adapter, modified from the official hiredis adapter

add new hiredis adapter, it seems better for C++
fix some style typo
Add redisReplyToString
Merge pull request #84 from trymuduo/hiredis_adapter

Add example of hiredis adapter for muduo.
Merge branch 'master' of https://github.com/chenshuo/muduo