Modified and beautified the documentation: * INSTALL.txt, doku/Makefile, doku/source/conf.py, doku/source/functionality.txt, doku/source/index.txt, doku/source/restrictions.txt, website/favicon.png, LICENCE.txt: added more details to the content of the documentation. some more configurations. * doku/source/LICENCE.txt: New. Added a licence-text (symlinking into the documentation). * doku/source/_static/favicon.png, doku/source/_static/logo_wide.png, doku/source/_templates/indexsidebar.html, doku/source/_templates/layout.html: Optic-cosmetics.