Catch ^C

[TheBlueMatt]

And tell users to use ^D.

[tnull]

Seems this is not as straightforward as one might think, at least if we want to make it work on all platforms. IIUC std does not support signal handling sufficiently, so we either handle this via unsafe libc code and try to catch all platform-dependent quirks, or just take a dependency on the ctrlc crate. Are we fine doing the latter?

[TheBlueMatt]

Bleh, lets just refuse to build on Windows :p. But, I don't think we need to try that hard, just doing the libc signal catch approach for Unixes should suffice.