Allow code-blocks in footnotes for LaTeX PDF output.
This is done via using a ``footnote environment``, provided by LaTeX
package footnotehyper which replaces old problematic package footnote.
No need to ship a custom tabulary anymore.
The footnote markers are silently removed from the table of contents and
do not end in the PDF bookmarks (the old code in ``sphinx.sty`` copying
``footmisc.sty`` was not satisfactory and has been deleted and replaced
by use of better ``\sphinxfootnotemark``.) Footnotes can be used also in
captions of literal blocks.
The cause of the issue was a clash about ``\titleref`` macro being already
defined in memoir class context. To avoid similar problems, this makes
the text styling macros
``\strong``, ``\code``, ``\bfcode``, ``\email``, ``\tablecontinued``,
``\titleref``, ``\menuselection``, ``\accelerator``, ``\crossref``,
``\termref``, ``\optional``,
also available with ``\sphinx`` prefix, with a conf.py boolean option to
let sphinx.sty only define ``\sphinx``-prefixed macros. As default value
is False, backwards compatibility is maintained.
On this occasion, some internal non-public macros have been renamed with
prefix ``\spx@``. The command
find . -name '*.sty' -exec grep -l \\\\spx@ {} \;
has been executed in TeXLive 2015 and 2016 installations to check no
package defines macros starting with ``\spx@``.
Some internal macros having public names (because they are written by
latex.py into the body of the latex document) have been renamed to have
``\sphinx`` prefix. The macros in sphinx.sty starting with \py@, or \DU,
or \PYG have not been modified. Similarly ``\release``, ``\version``,
``\releasename``, etc... have not been renamed.
test_numref_on_bable_disabled and test_numref_with_language_el are mainly
used for testing babel (not for numref). But now we added enough testcases
for babel.
