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.

Committed as r60938 (python) and r60939 (sphinx). Thanks for the nice patch!