rename DbPool to DBPool, and add todo
add some advice in dbpool_server.cpp
Merge https://github.com/sinofool/dbpool into bbc: direct use
client->ice_timeout(300) is ok

Conflicts:
	server/dbpool_server.cpp
add compare in set
1. add log to debug and error
2. when return data to remote client, return a copy
3. add compare for set
Merge pull request #2 from tgch/master

server debug