Fix #2629. Add new config option ``latex_keep_old_macro_names``

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.

1 files changed, 6 insertions, 0 deletions

diff --git a/sphinx/quickstart.py b/sphinx/quickstart.py
index 1f14c0d09..4680fecd4 100644
--- a/sphinx/quickstart.py
+++ b/sphinx/quickstart.py
@@ -359,6 +359,12 @@ latex_documents = [
 #
 # latex_appendices = []
 
+# It false, will not define \strong, \code, \titleref, \crossref ... but only
+# \sphinxstrong, ..., \sphinxtitleref, ... To help avoid clash with user added
+# packages.
+#
+# latex_keep_old_macro_names = True
+
 # If false, no module index is generated.
 #
 # latex_domain_indices = True