Consolidate logging

[Naton1]

Some things uses System.out.println to log, and some things use java.util.logging's Logger. Should make this consistent. Since this is a base server, recommend adding slf4j and replacing everything with that so then people who use this can use whatever logging backend they want. Could use slf4j-simple as a default.

[tobywisener]

Really good shout, will look into this