Hide page bar by default and move navigation controls into toolbar
This patch modernizes and improved Okular's default UI by hiding the page bar and adding its navigation controls into the toolbar, separating it from other elements with expanding spacers. This yields the following improvements:
- Reduced redundancy from having multiple zoom tools
- Increase in the amount of vertical space available for reading documents
- Aesthetic improvement of a more modern toolbar layout with expanding spacers to separate logical groups
Here's what Okular's main window look like with this change:
By hiding the page bar, we do lose the display of page size for the current page when viewing a document with multiple page sizes, but I don't think this is a major issue since multi-page-size documents are rare and the size information is fairly obvious just by looking at the document. Also with !179 (merged) the fact that the document contains multiple pages will be visible in the Properties dialog.