APIchanges: mark the place where 0.7 was cut.

doc/APIchanges

@@ -214,15 +214,22 @@ API changes, most recent first:
 
 2011-07-10 - a67c061 - lavf 53.3.0
   Add avformat_find_stream_info(), deprecate av_find_stream_info().
+  NOTE: this was backported to 0.7
 
 2011-07-10 - 0b950fe - lavc 53.6.0
   Add avcodec_open2(), deprecate avcodec_open().
+  NOTE: this was backported to 0.7
+
   Add avcodec_alloc_context3. Deprecate avcodec_alloc_context() and
   avcodec_alloc_context2().
 
 2011-06-23 - 67e9ae1 - lavu 51.8.0 - attributes.h
   Add av_printf_format().
 
+------------------------------8<-------------------------------------
+                   0.7 branch was cut here
+----------------------------->8--------------------------------------
+
 2011-06-16 - 05e84c9, 25de595 - lavf 53.2.0 - avformat.h
   Add avformat_open_input and avformat_write_header().
   Deprecate av_open_input_stream, av_open_input_file,