New upstream developer release 5.2.0dr4

- Attestation IMV/IMC supports IMA-NG measurement format now
- Aikgen tool to generate an Attestation Identity Key bound
  to a TPM
- PT-EAP transport protocol (RFC 7171) for TNC
- vici plugin provides IKE Configuration Interface for charon
- Enabled support for acert for checking X509 attribute certificate
- Updated patches
- Updated spec file with minor cleanups

.gitignore

@@ -10,3 +10,6 @@
 /strongswan-5.1.2.tar.bz2
 /strongswan-5.1.3rc1.tar.bz2
 /strongswan-5.1.3.tar.bz2
+/strongswan-5.2.0dr4.tar.bz2
+/strongswan-5.2.0dr4.tar.bz2.md5
+/strongswan-5.2.0dr4.tar.bz2.sig