re-compiled with golang 1.7 stable.
add aes-128, aes-192 encryptions.

golang 1.7 稳定版重制。
增加 aes-128, aes-192加密

(Update 20160818: revert a minor unstable changes, if you feel something strange, please re-download. )

MD5 (kcptun-linux-amd64-20160816.tar.gz) = 52cd6456b54cce01627e629767dc9deb
MD5 (kcptun-linux-386-20160816.tar.gz) = 20573d91391e38f48e97f32f0ffc8a34
MD5 (kcptun-darwin-amd64-20160816.tar.gz) = d0b272376029f9ae518ae05ff0afb727
MD5 (kcptun-darwin-386-20160816.tar.gz) = 9acc1ad52c335fe7f04c967d10104b1c
MD5 (kcptun-windows-amd64-20160816.tar.gz) = a2c5563ab2053976441d5a7bbffa98c2
MD5 (kcptun-windows-386-20160816.tar.gz) = f709eb7c813b586a5fdb24ee07e31df0
MD5 (kcptun-freebsd-amd64-20160816.tar.gz) = 0b3417ffc9c4ff418a14a0f76871338e
MD5 (kcptun-freebsd-386-20160816.tar.gz) = 9e367205d268a51794ce5e3310584c53
MD5 (kcptun-linux-arm-20160816.tar.gz) = 16ffab9f9a0084ae4141a9648e4b2cfc