[LyX/master] DocBook: implement theorems.

[Thibaut Cuvelier]

commit ca1ca4326b027d7781c6ff31c1dfb1b5e4e53d8c
Author: Thibaut Cuvelier <tcuvelier at lyx.org>
Date:   Mon Aug 31 02:39:37 2020 +0200

    DocBook: implement theorems.
    
    This is a minimal implementation, as DocBook lacks a serious way of encoding all of this. Maybe a <formalpara> could do the trick, but I'd need to find a way to shoehorn a title through the styles (i.e. a first complete tag):
    
    Theorem: Bla bla
    
    <formalpara>
    <title>Theorem</title>
    <para>Bla bla</para>
    </formalpara>
    
    This would also only be a solution for single-paragraph things, as formalpara only allows one paragraph. Or a sidebar, but it's semantically very remote.

 autotests/export/docbook/Additional_lyxcode.lyx    |  164 ++++++++++++++++++++
 autotests/export/docbook/Additional_lyxcode.xml    |   35 ++++
 development/DocBookToDo                            |   23 +++-
 lib/layouts/theorems-ams-bytype.inc                |   26 +++
 lib/layouts/theorems-ams-chap-bytype.inc           |   26 +++
 lib/layouts/theorems-ams-extended-bytype.module    |   64 ++++++++
 .../theorems-ams-extended-chap-bytype.module       |   64 ++++++++
 lib/layouts/theorems-ams-extended.module           |   64 ++++++++
 lib/layouts/theorems-ams.inc                       |   26 +++
 lib/layouts/theorems-bytype.inc                    |   26 +++
 lib/layouts/theorems-case.inc                      |    2 +
 lib/layouts/theorems-proof-std.inc                 |    2 +
 lib/layouts/theorems-proof.inc                     |    2 +
 lib/layouts/theorems-starred.inc                   |   28 ++++
 lib/layouts/theorems-without-preamble.inc          |   42 +++++
 lib/layouts/theorems.inc                           |   28 ++++
 16 files changed, 621 insertions(+), 1 deletions(-)