Add missing changelog entry for last commit.
svn:r551
o The kqueue implementation now catches signals that are raised after event_add() is called but before the event_loop() call. This makes it match the other implementations.
o The kqueue implementation now restores original signal handlers correctly when its signal events are removed.
o Check return value of event_add in signal.c
+ o Add a more powerful evbuffer_readln as a replacement for evbuffer_readline. The new function handles more newline styles, and is more useful with buffers that may contain a nul characters.
Changes in 1.4.0: