59658a8de7 changed uv_thread_self()
to return uv_thread_t, but uv_thread_t is a thread's HANDLE while
uv_thread_self() returns the current thread's id.
This means that uv_thread_equal() is also broken, as we are
potentially comparing HANDLES to ids.
Changed uv_thread_self() to return the current thread's creation handle.
Fixed small doc issue.
6591d000d1