Feature: customizable index-page-title

These commits add a new command line-switch ***--title*** (as well as project-field) to override the index-page's title to make SEO's happier. The default value ***index*** is the same as the hardcoded value before.

I think this special “way” is necessary because you usually can not annotate things like the *README.md* with a title-tag and you can not guarantee that the first header is always a sane one (suitable as index-title). Therefore I created this patch.

Would be glad if you pull it …

Thanks & Cheers,
Stephan