todo

Last Update: Jan 22 2009 可靠UDP传输, 一套高效的基于windows平台的C++ 开发库

# rename core.* to socket.*
# rename contorl.* to kbase.*
add selectEx
add accurate receiver buffer size calculation in our-of-order message delivery.
add file transfer under messaging mode
reduce frequency of ACK2s
add identification code for each UDT packet