* dbus/dbus-sysdeps.c (_dbus_set_errno_to_zero)
	(_dbus_get_is_errno_nonzero, _dbus_get_is_errno_eintr)
	(_dbus_strerror_from_errno): family of functions to abstract
	errno, though these are somewhat bogus (really we should make our
	socket wrappers not use errno probably - the issue is that any
	usage of errno that isn't socket-related probably is not
	cross-platform, so should either be in a unix-only file that can
	use errno directly, or is a bug - these general errno wrappers
	hide issues of this nature in non-socket code, while
	socket-specific API changes would not since sockets are allowed
	cross-platform)