TCP connection should not crash the program if they are closed from within a finalizer. Instead, give a warning if such a class has leaked.
(cherry picked from commit 2c0adbc56170571991781cebf1e3aac1549828ad)
UDP receive timeout doesn't work for the libevent driver.
(cherry picked from commit 443e0713ded4d2eaf5e9bc6c24ed79069d2a92dd)
(cherry picked from commit 6997dc304c2d09511c409bd18f847bac330a06a3)
