Note: This is a major release, and this version, 4.1.0, is only compatible with versions 4.1.X.
New features
Lots of speed improvements. Compression is faster using Huffman (2049743, thanks @nicolashardy). Connecting to relays is faster by using Goroutines (08c84e9).
Configuration file. You can now set flags that will be used automatically from a configuration file, unless they are overridden by CLI flags (dd03cdc, 81bc06e, 1ae1171).
Different PAKE elliptic curves. You can now change the PAKE elliptic curve used for the protocol (304355a).
Sender and recipient check versions. croc is only compatible with other croc programs that have the same major version (e.g. 4.1 and 4.1). This is now checked automatically (9349496).
Bug fixes
Better sender/recipient communication. Canceling croc now communicates better between the recipient and sender, and it will quickly close the other instead of hanging (c2dd909, 6a07e15)
Removed unused dependencies (9e7661c).