session CHANGE new killed-by atrribute of every session

Also 2 new setters added.
diff --git a/src/session.c b/src/session.c
index 88eb17d..6ee961e 100644
--- a/src/session.c
+++ b/src/session.c
@@ -294,7 +294,7 @@
 }
 
 API NC_SESSION_TERM_REASON
-nc_session_get_termreason(const struct nc_session *session)
+nc_session_get_term_reason(const struct nc_session *session)
 {
     if (!session) {
         ERRARG("session");
@@ -305,6 +305,17 @@
 }
 
 API uint32_t
+nc_session_get_killed_by(const struct nc_session *session)
+{
+    if (!session) {
+        ERRARG("session");
+        return 0;
+    }
+
+    return session->killed_by;
+}
+
+API uint32_t
 nc_session_get_id(const struct nc_session *session)
 {
     if (!session) {