Replaced original yamux with smux.
smux provides a _Token bucket_ controlled receiving, which leads to smoother bandwidth graph. (see smux here) and lower memory footprint.
_Warning: SMUX is incompatible with all previous releases, you have to upgrade both client & server_.
Issues about SMUX can be found & discussed here : #168
compiler: go version go1.7 darwin/amd64
kcptun version: 3db63cdsmux version: xtaci/smux@f4d95a8
kcp-go version: xtaci/kcp-go@108b5ca
MD5 (kcptun-linux-amd64-20160904.tar.gz) = 4c8118d27b5658e9dfa9f1a1ebf89a23
MD5 (kcptun-linux-386-20160904.tar.gz) = 33ad69223a68650986b6e98dbe5599e5
MD5 (kcptun-darwin-amd64-20160904.tar.gz) = 2715ed67a5e1d11e8f3e9b988b44ef27
MD5 (kcptun-darwin-386-20160904.tar.gz) = edab932a2c2d8fc42bb9cf2b20a87bfe
MD5 (kcptun-windows-amd64-20160904.tar.gz) = 26d7f7ff2ed89dac368e296dac656558
MD5 (kcptun-windows-386-20160904.tar.gz) = 7456cd01c09bb0c1369b5af3954287ee
MD5 (kcptun-freebsd-amd64-20160904.tar.gz) = 5bd55bec45e3a1c2ceb2e3becd5d6029
MD5 (kcptun-freebsd-386-20160904.tar.gz) = ca8c99d88eca2afda03c82df626e56d0
MD5 (kcptun-linux-arm-20160904.tar.gz) = 9e47e31b32988aa3b1dc5aca80851bba