Revert "Remove tests that depend on TLS or X.509"

This reverts commit 9afb2e992136db3fae9a669c3faaf6d5d27602a8.

Conflicts:
* include/CMakeLists.txt
  * "Make config.h available" comment: there has been a change
    adjacent to where it was removed. Just re-add what was removed.
* tests/CMakeLists.txt:
  * compat.sh: there has been a change immediately before where it was
    removed. Just re-add what was removed.
diff --git a/tests/scripts/travis-log-failure.sh b/tests/scripts/travis-log-failure.sh
new file mode 100755
index 0000000..9866ca7
--- /dev/null
+++ b/tests/scripts/travis-log-failure.sh
@@ -0,0 +1,36 @@
+#!/bin/sh
+
+# travis-log-failure.sh
+#
+# This file is part of mbed TLS (https://tls.mbed.org)
+#
+# Copyright (c) 2016, ARM Limited, All Rights Reserved
+#
+# Purpose
+#
+# List the server and client logs on failed ssl-opt.sh and compat.sh tests.
+# This script is used to make the logs show up in the Travis test results.
+#
+# Some of the logs can be very long: this means usually a couple of megabytes
+# but it can be much more. For example, the client log of test 273 in ssl-opt.sh
+# is more than 630 Megabytes long.
+
+if [ -d include/mbedtls ]; then :; else
+    echo "$0: must be run from root" >&2
+    exit 1
+fi
+
+FILES="o-srv-*.log o-cli-*.log c-srv-*.log c-cli-*.log o-pxy-*.log"
+MAX_LOG_SIZE=1048576
+
+for PATTERN in $FILES; do
+    for LOG in $( ls tests/$PATTERN 2>/dev/null ); do
+        echo
+        echo "****** BEGIN file: $LOG ******"
+        echo
+        tail -c $MAX_LOG_SIZE $LOG
+        echo "****** END file: $LOG ******"
+        echo
+        rm $LOG
+    done
+done