Merge branch 'android-app'

This branch introduces a userland IPsec implementation (libipsec) and an
Android App which targets the VpnService API that is provided by Android 4+.

The implementation is based on the bachelor thesis 'Userland IPsec for
Android 4' by Giuliano Grassi and Ralf Sager.

src/libcharon/sa/ike_sa.c

@@ -488,7 +488,7 @@ METHOD(ike_sa_t, send_keepalive, void,
 		data.ptr[0] = 0xFF;
 		data.len = 1;
 		packet->set_data(packet, data);
-		DBG1(DBG_IKE, "sending keep alive");
+		DBG1(DBG_IKE, "sending keep alive to %#H", this->other_host);
 		charon->sender->send_no_marker(charon->sender, packet);
 		diff = 0;
 	}

src/libcharon/sa/ike_sa.h

@@ -43,6 +43,7 @@ typedef struct ike_sa_t ike_sa_t;
 #include <config/peer_cfg.h>
 #include <config/ike_cfg.h>
 #include <credentials/auth_cfg.h>
+#include <utils/packet.h>
 
 /**
  * Timeout in seconds after that a half open IKE_SA gets deleted.

src/libcharon/sa/ikev2/tasks/ike_mobike.h

@@ -26,7 +26,7 @@ typedef struct ike_mobike_t ike_mobike_t;
 #include <library.h>
 #include <sa/ike_sa.h>
 #include <sa/task.h>
-#include <network/packet.h>
+#include <utils/packet.h>
 
 /**
  * Task of type ike_mobike, detects and handles MOBIKE extension.