firmware: first half of 17.1 upgrade code

With this it's possible to upgrade manually, but not from
the console menu.  The two "firmware" files for the EOL
annoucement and the pointer to the next release name are
missing.  They will be added in 16.7.14_1.

src/etc/pkg/fingerprints/OPNsense/trusted/pkg.opnsense.org.20161210

+function: "sha256"
+fingerprint: "1436d53cd170457e43ef66a36e11b8cf25593cd24ae4e7222d4091c710d12b3a"

src/etc/rc

@@ -232,6 +232,14 @@ echo "done."
 # Set up the correct php.ini content
 /usr/local/etc/rc.php_ini_setup
 
+# Perform major updates
+for STAGE in B P; do
+	if opnsense-update -${STAGE}; then
+		# ideally reroot with `-r', but panics on ZFS
+		reboot
+	fi
+done
+
 # Startup configd
 /usr/local/etc/rc.d/configd start