Merge pull request #43 from matrix-org/pedroc/android_e2e_dev

.../src/main/java/org/matrix/olm/OlmInboundGroupSession.java

android/olm-sdk/src/main/java/org/matrix/olm/OlmManager.java

android/olm-sdk/src/main/java/org/matrix/olm/OlmMessage.java

...src/main/java/org/matrix/olm/OlmOutboundGroupSession.java

android/olm-sdk/src/main/java/org/matrix/olm/OlmSession.java

android/olm-sdk/src/main/java/org/matrix/olm/OlmUtility.java

android/olm-sdk/src/main/jni/Android.mk

android/olm-sdk/src/main/jni/Application.mk

android/olm-sdk/src/main/jni/olm_account.cpp

android/olm-sdk/src/main/jni/olm_account.h

android/olm-sdk/src/main/jni/olm_inbound_group_session.cpp

android/olm-sdk/src/main/jni/olm_inbound_group_session.h

android/olm-sdk/src/main/jni/olm_jni.h

android/olm-sdk/src/main/jni/olm_jni_helper.cpp

android/olm-sdk/src/main/jni/olm_jni_helper.h

android/olm-sdk/src/main/jni/olm_manager.cpp

android/olm-sdk/src/main/jni/olm_manager.h

android/olm-sdk/src/main/jni/olm_outbound_group_session.cpp

android/olm-sdk/src/main/jni/olm_outbound_group_session.h

android/olm-sdk/src/main/jni/olm_session.cpp