Renamed the Swift package to Cbsspeke because this is going to be the low-level interface to the C code.  We'll build another package to be the nice Swifty interface.

Renamed monocypher.(c|h) to minimonocyper.(c|h) to make it clear that these are not the original versions

Cut out all of the encryption stuff from monocypher.  Should now be OK to export from the US without issue.