algorithm improvement in updater.go

Merge pull request #74 from jinq0123/master

use heap.Fix() instead of Pop() and Push()

add a builtin blacklist

Merge pull request #65 from AudriusButkevicius/master

Add blacklist

a faster nonce generator

v3.22

remove the lock in rand

switch back upstream FEC library for better community & performance

v3.21

switch back upstream library, and keep the better xor

a more efficient slice zeroing by copying

v3.20

using copy to zero a slice is much more efficient in FEC

switch to a new rs package

https://github.com/templexxx

improve packet session lookup

improve packets session lookup speed by caching last session(locality assumption).

hide internal structs

1. hide internal structs
2. more comments for godoc

v3.16

add a precondition before heap operations

v3.15

fix incorrect interval = 0  when SetNoDelay hasn't called