Tabbed document viewer in Qt

qpdfview uses Poppler for PDF support, libspectre for PS support, DjVuLibre for DjVu support, CUPS for printing support and the Qt toolkit for its interface. Current features include: * Outline, properties and thumbnail panes. * Scale, rotate and fit. * Fullscreen and presentation views. * Continuous and multiple-page layouts. * Search for text. * Configurable tool bars. * Configurable keyboard shortcuts. * Persistent per-file settings. * SyncTeX support. * Rudimentary annotation support. * Rudimentary form support. * Support for PostScript and DjVu documents.