Upstream changes:
3.8 Sun Aug 9 15:30:10 CEST 2009
- implement $loop->signal/signal_ns.
- (libev) incompatible change: do not necessarily reset signal
handler to SIG_DFL when a sighandler is stopped.
- (libev) ev_default_destroy did not properly free or zero some
members, potentially causing crashes and memory corruption on
repated ev_default_destroy/ev_default_loop calls.
- (libev) take advantage of signalfd on GNU/Linux systems.
- (libev) document that the signal mask might be in an unspecified
state when using libev's signal handling.
- (libev) take advantage of some GNU/Linux calls to set
cloexec/nonblock on fd creation, to avoid race conditions.
- implement internal glue code to interface more efficiently
with AnyEvent.