Added basic libuv support to cjdns.
Switched to using uv_poll.

It seems I jumped the gun by using standard uv functions.  However
using uv_poll should preserve existing functionality, while moving
cjdns onto the libuv loop.
Added a return to Event_socketRead.

This is exactly what was returned by the original implementation.
The return may not be useful, but it's probably better than a void.
Fixed broken CMake libuv implementation.

- The FindLibuv.cmake file never actually set LIBUV_FOUND which
  caused it to ALWAYS fetch/build libuv itself.  This has been
  fixed.

- OS X builds were completely broken.  The libuv Makefile does
  not link its static library to the necessary CoreServices library.
  This has also been fixed.
This now builds properly on Linux as well.
Updated to perl and python modules to use UDP.
Stop logging if there is an error sending a message.
Merged xulfer's libuv port.
Switched the event loop to libuv