oll-doc: diversify CSS files

Have two independent CSS files to be used for in-app and
in-browser viewing, and include other stuff from there.

This is very sketchy so far.
oll-doc: Generate HTML page title
oll-doc: re-read current snippet on lib reread

When the library is reread the current snippet is displayed
again (if the name is still there). So any external changes to
the snippet will be reflected in the GUI.
oll-doc: Create navigation content by using templates

This is of course significantly better than the initial sketch
Merge branch 'doc-script' into reorganization