Patch #1489771: update syntax rules in Python Reference Manual.
Python 2.5 added support for explicit relative import statements and
yield expressions, which were missing in the manual.
Also fix grammar productions that used the names from the Grammar file,
markup that broke the generated grammar.txt, and wrap some lines that
broke the pdf output.  Will backport.
diff --git a/Misc/NEWS b/Misc/NEWS
index 791e954..3ebf16e 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -718,6 +718,9 @@
 Documentation
 -------------
 
+- Patch #1489771: the syntax rules in Python Reference Manual were
+  updated to reflect the current Python syntax.
+
 - Patch #1686451: Fix return type for
   PySequence_{Count,Index,Fast_GET_SIZE}.