[Pasdoc-main] Default CSS small improvements (use default font), and other

[Michalis K. <mic...@gm...>]

Two small changes:

1. I removed the ugly line "font-size: 12px;" from our CSS. Setting the
font size explicitly, for the whole document, in pixels, is really bad
--- I wanted to remove it since a long time, but didn't have the courage
(your docs will look differently!). But it's about time:)

You can check out e.g. new autodoc to see how it looks:

  http://pasdoc.sourceforge.net/autodoc/html/index.html

Also, other small fixes to CSS and HTML around tipue, also about nicer
CSS and valid HTML. Also also about HTML friendly for mobiles.

Long-term, we should just use Bootstrap, there's even a ticket about it:
https://sourceforge.net/p/pasdoc/feature-requests/50/ . In the meantime,
these little fixes at least fix the most ugly problems.

2. Also, the next binary release will include our tools: Pascal
preprocessor (pascal_pre_proc) and utilities file_to_pascal_string,
file_to_pascal_data. They are generally useful, and it's time to show
them to the world:)

Michalis