Improve overall (networking) performance

The asynchronous socket code is the next candidate to get replaced by external library that does things better and is actually maintained. libuv is a multi-platform support library with a focus on asynchronous I/O.

Apart from the networking I/O, the library can also other things in a multiplatform manner:

• File system operations
• Thread pool work scheduling
• DNS utility functions
• Shared library handling
• Threading and synchronization utilities
• Miscellaneous utilities

The library is well maintained, and it would remove a great burden of maintaining our custom code. I asked @muks to look into it.