GSOC Report Week 6

Last week I finished up a lot of the things that were due for the first
evaluation/ phase of the project.

* Make the information screen work properly
  * Display correct URL
  * Mix better with LibreOffice slideshow (still not perfect)
* Various minor additions to the run scripts
* Set default values for presentations (timing, transitions,
  always-fullscreen)
* When only playing one (1) presentation, loop it
* Control panel Play/Stop buttons work as intended; indicate currently
  playing presentation
* Started work on the "Impress JS" sub-project. (There's already a
  project with this name, so a new name is needed)

Thorsten suggested to create a JavaScript-/web-based Impress Remote to
use with this project. I've divided it into three parts:

A "LibreSign"-specific (LibreOffice Appliances GSOC 2019 i.e. this
project) web application.
A JavaScript library implementing the Impress Remote Protocol.
A Python WebSocket server also implementing the Impress Remote Protocol
and acting as a relay between the clients and LibreOffice.

The intended use is primarily for "LibreSign", to be able to control
slideshows without installing the Impress Remote app.