Makefile: make inkscape rule compatible with Inkscape 0 and 1

See merge request !2

beamerthemetptng.sty: Add theme option authorinfoot

See merge request !1

Enable the possibility to display the author name in the "institute
field".

The declarations of the option authorinfoot is an adapted copy-paste of the
textheighthack option.

Then, depending on the activation of the option, the institute field is
modified in "institute in head/foot"
For now, the following structure is : <author> -- <institute>

We may want to let the user to decide the separating characters
(the double dash is now in the sty ; user has to change the sty to
change the separation)

Tarik Graba authored Jun 25, 2020 and Tarik Graba committed Jun 01, 2021

https://wiki.inkscape.org/wiki/index.php/Release_notes/1.0#Command_Line

We do not use brown blocks any more, replaced by light gray

When using Lualatex, -- is replaced by en-dash only if the text-tex
mapping is enabled for a certain font (see fontspec) whereas the
\textendash is guaranteed to work in all font encodings/tools

Bump release version.

Bump release version.

Bump release number.

Bump release number.

Begin rationalizing file names, rename theme.
Slight fix in content frame.

Bump release number.

Work around Beamer bug #614 (appears when left margin > right margin).

Bump release number.

If the short date is not defined it will fullback to the full date

Create version 0.8.1.

Create temporary version 0.8.0.