made Python 3.3 compatible
remove unnecessary `encode()` calls

 - PyZMQ provides `send_string()` wrapper method to send unicode strings
   directly (with default `encoding` parameter "utf-8").
removed further unnecessary encoding conversions
more error-tolerant
implemented play time tracking and db versioning
Merge remote-tracking branch 'origin/master' into py3k
minor fix
apply readtable_timedelta() to logout, too
fixed a minor bug that prints raw mcid in IRC when logging in; removed comma in readable_timedelta()
Merge master (supports for Minecraft 1.7)
Replace "/say" commands with "/tellraw" commands for Minecraft 1.7+
Utilize formatting inheritance of tellraw command
Add the server password argument (make it blank string if not required)