Issue 23729:  Document ElementTree namespace handling and fix an omission in the XPATH predicate table.

Based on patch by Nikolaus Rath.

#17741

I was confused by the text saying that read_events "iterated", since it
actually returns an iterator (that's what a generator does) that the
caller must then iterate.  So I tidied up the language.  I'm not sure
what the sentence "Events provided in a previous call to read_events()
will not be yielded again." is trying to convey, so I didn't try to fix that.

Also fixed a couple more news items.

Also added versionadded for for fish/csh, fixed indentation of versionadded
for ElementTree.write, and make the behavior of shelf as a context manager
explicit in the docs.

In 3.3 iterparse accepts a tuple in events (the C accelerator enforces this).
This limitation was lifted in Python 3.4

- this was an internal implementation detail for iterparse
- this has been changed to use a new private method instead
- XMLPullParser.close docs are now more explicit about not
  returning a root element and instead direct users towards
  read_events
- also added missing docstrings and clarified some details
  related to exactly *when* events are consumed from the
  internal queue

(Initial patch by Stefan Behnel)

The latter is more ambiguous.

Related to issue #17741

The new names are hopefully more descriptive and consistent. If you feel you
don't agree with this change, *please* read issue 17741 first - there's a lot of
discussion in there.

Using ``method`` markup because the method is on a callback object, not an
explicitly documented method. :meth: markup creates links within the current
class which is incorrect.

In addition, indent the paragraph correctly.

The return value of close() is not always a toplevel element. It depends on
what the underlying target returns. By default, TreeBuilder returns the
toplevel document element.

the doc for iterparse.

Issue #17741: Add ElementTree.IncrementalParser, an event-driven parser for non-blocking applications.

Closes #4159: add LaTeX tabular column specifications to tables that otherwise are cut off or have overlapping text.

C implementation.

Cleanup the docs ElementTree a bit and describe the default_namespace parameter. In the code, replace the old outdated Doxygen-ish comment above ElementTree.write by a proper docstring.

serialization functions - short_empty_elements. It controls how elements
without contents are emitted.

Patch by Serhiy Storchaka. Feature initially proposed by Ariel Poliak.

Issue #16082: clarify the documentation of tostring[list] saying that it may generate a bytestring, depending on the given encoding.

Issue #12322: clarify xpath reference for cases where the path reaches ancestors of the start element. Also add missing markup for a None. Thanks to patrick vrijlandt and Mike Hoy for the report and initial patches.