Replace the unmaintained libev with libuv

[theoparis]

It seems like libev hasn't been updated for 8 years, and there is a PR that fixes compatibility with C++17 that will never be merged officially. Additionally, libev seems to have design issues - I tried to fork it but it turns out the ev_loop struct is defined in a C file instead of a .h file and it is hard to move it to the h file without rewriting the macro system it uses.

Example of the design issues from there being no struct defined in ev.h:

The official website also seems to only use http 😬