[doc][m2sci_equivalents] A bit of cleaning and update

[doc][m2sci_equivalents] A bit of cleaning and update

  * many misc. fixes/updates (noticeably after Scilab 5=>6)
  * delete all pages that tell nothing more than
       Matlab       Scilab
       theFun       theFun
  * deactivate non-runnable <programlisting>
  * explicits more list of compared syntaxes

  After merging [m2sci_equivalent] separate module into [m2sci],
  This is a second step to improve m2sci documentation.

  Next one could be to merge corresponding m2sci_equivalent and
  mtlb_# pairs of pages.

Change-Id: I0677117d98108982d354f2be6d8aa1175bdb2aba