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/Makefile b/Makefile
index 026c637..8e72bd1 100644
--- a/Makefile
+++ b/Makefile
@@ -101,6 +101,8 @@
 covtest:
 	$(MAKE) check
 	programs/test/selftest
+	tests/compat.sh
+	tests/ssl-opt.sh
 
 lcov:
 	rm -rf Coverage