DOC: Fix a few typos

these are mostly spelling mistakes, some of them might be candidate for
backporting as well.
diff --git a/include/types/connection.h b/include/types/connection.h
index 8a0ce79..3a7de64 100644
--- a/include/types/connection.h
+++ b/include/types/connection.h
@@ -56,7 +56,7 @@
 	int wait_reason;
 };
 
-/* A connection handle is how we differenciate two connections on the lower
+/* A connection handle is how we differentiate two connections on the lower
  * layers. It usually is a file descriptor but can be a connection id.
  */
 union conn_handle {