Support chacha20 and salsa20, along with other small fixes.
For OS X and Linux, run the following command to update
curl -L git.io/cow | bash
For Windows, please download from http://dl.chenyufei.info/cow/latest
Changes:
- Support new encryption method "chacha20" and "salsa20"
- Avoid biased parent proxy selection for hash load balacing
- Fix AirDrop on OS X when using PAC
- Fix failed start with corrupted stat file
- Support changing the estimate timeout target