Include <sys/select.h> to get select

These files currently depends on the wrapper <stdlib.h> file indirectly
including a header that provides select().

from Jonas 'Sortie' Termansen

ok deraadt@ tedu@
Include <sys/time.h> to get struct timeval

The crypto/bio/bss_dgram.c file assumes that another file indirectly
includes <stdlib.h> that includes <sys/time.h>.

from Jonas 'Sortie' Termansen

ok deraadt@ tedu@
constify strerror return value

There is no intention to modify the string returned by strerror and
doing so is forbidden by the standard.

from Jonas 'Sortie' Termansen

ok tedu@ deraadt@