- (djm) [regress/cert-hostkey.sh] Fix regress failure on platforms that
    skip one or more key types (e.g. RHEL/CentOS 6.5); ok dtucker@
 - (dtucker) [configure.ac] Make PIE a configure-time option which defaults
   to on platforms where it's known to be reliably detected and off elsewhere.
   Works around platforms such as FreeBSD 9.1 where it does not interop with
   -ftrapv (it seems to work but fails when trying to link ssh).  ok djm@
 - (dtucker) [aclocal.m4] Differentiate between compile-time and link-time
   tests in the configure output.  ok djm.
 - (tim) [platform.c session.c] Fix bug affecting SVR5 platforms introduced
   with sftp chroot support. Move set_id call after chroot.
 - (djm) [aclocal.m4] Flesh out the code run in the OSSH_CHECK_CFLAG_COMPILE
   and OSSH_CHECK_LDFLAG_LINK tests to give them a better chance of
   detecting toolchain-related problems; ok dtucker