Log Message:
Update to libevent-1.3d. ChangeLog is not available but from the homepage:

libevent-1.3d:
Bug fixes in the HTTP layer.

libevent-1.3c:
Small bug and portability fixes.

Worth mentioning is that patch-ab and patch-ac were applied upstream.
As usual with libevent, this breaks the ABI due to .so naming, so a
small revbump sweep will be needed.