Improve Project Details

[vkbo]

This PR makes a few improvements to the Contents tab on the Project Details dialog:

• Remove indentation of chapter titles, and instead make non-chapter titles stand out by using bold, italic and underline.
• Allow the user to select which page is the first page to start counting from. The preceding pages are then counted with roman numbers as is customary in front matter, and the story progress column ignores these pages.