add epoll implementation to libwine_port (take 3)

[Mike McCormack]

Boaz Harrosh wrote:

> [Q] Does that mean that we directly check if it is supported in kernel, 
> bypassing glibc all together? how do we avoid conflicts with glibc?

The definitions are wrapped by #ifndef HAVE_EPOLL_CREATE, which is set 
by a configure check.

The end result is that we use this code if libc does not provide an 
epoll implementation, and use libc's if it is available.

Mike