BUG: the builtin LaTeX/P DF exporter mislabels source blocks as figures.

[Emmanuel Charpentier <emm.charpentier@free.fr>]

I shall report formally the problems mentioned in 
http://lists.gnu.org/archive/html/emacs-orgmode/2019-04/msg00240.html,
trying to isolate them as much as possible. I'll start with the
simplest (and, IMHO, the most annoying).

Whereas the HTML exporter correctly recognize a source block as such,
the LaTeX/PDF exporter does not.

This can be demonstrated in a (minimal) org file using *only* the
built-in tools (no external packages), where a source block is labelled
as such by the HTML exporter but as a figure by the LaTeX exporter.The
generated LaTeX source shows a suspicious
"\captionof{figure}{\label{orgf2d4160}" in the export of the source
block.

Further tests (not shown) show that the proble persists when org-mode
is set up to use the minted package for LaTeX export of source blocks
(minted is indeed used, but the block is s still mislabeled).

This example also exhibits some cosmetic problems (spacing) that will
be ignored for now.

The org source and resulting pdf and html files are available here : 
https://drive.google.com/drive/folders/1bQmaefiztW9ZDRNLcjOD_WbEmTg4d8dG?usp=sharing