Abstracted xpdf's Outline to a Dom Tree. Fixed MERGE tags through the code.
Added comments (documentation) to KPDFDocument class and other classes in
document.h. Changed a little Generator interface.
Moved code from toc.h/.cpp to GeneratorPDF and shrinked a lot.

TODO (now): Convert TOC (widget) to use the Dom tree as data source.

svn path=/branches/kpdf_experiments/kdegraphics/kpdf/; revision=369914