syntax highlighting customization file

[Patrice Dumas]

Hello,

To celebrate @example language new argument I did a customization file
highlight_syntax.pm that uses source-highlight to do syntax highlighting
of @example fragments, for HTML output.  A customization variable
HIGHLIGHT_SYNTAX_DEFAULT which should be set after loading the init file 
can additionally be set to specify a language when there is no argument
for @example.

If you want some specific mapping of language that you customarily use 
to the languages as expected by source-highlight, that are obtained by 
 source-highlight --lang-list
(before the = sign), you can tell here, such that it can be added to the
%languages_name_mapping mapping in highlight_syntax.pm.

-- 
Pat