0024431: Using svg-images in the documentation

0024431: Using svg-images in the documentation

Documentation generator improved to automatically convert SVG images to PDF when PDF documents are generated. This is done with Inkscape thus it becomes necessary for generation of PDF documents.

Doxygen alias "figure" added for easy insertion of images with single command for both HTML and PDF output.

Documentation is updated.

Reviewed documentation.md and added more recommendations on Document Syntax.
Introduced existing svg images in the documentation.

Description of formatting of plain text, code blocks, and references revised.
Snapshot of structure of dox folder is updated.
Copyright year is corrected in PDF documents to be always the current one.

Some grammar corrections.