The new doc framework highlights python code, and looks very nice.
However, some snippets are not parseable by the compiler, and are thus
left unhighlighted. For example:
http://docs.python.org/dev/whatsnew/2.6.html#the-contextlib-module

The vast majority of misses is because of lines containing "...", which
is not a valid expression (except in slices).
The attached patch tries to recognize some common patterns, and replaces
"..." by some valid identifier; "... continue processing ..." is also
transformed. 

Note that the replacements are done only to get a better answer to "is
this block a python code"; pygment still works on the original string.

I checked that all new highlighted blocks are actually python snippets.
(actually, except one in configfile.rst; but others similar blocks on
the same page were already wrongly given to the python lexer)

The patch also corrects some easy syntax errors in samples.