merged in all the changes in my current gimp-poppler tree that don't need
* plug-ins/common/poppler.c: merged in all the changes in my current gimp-poppler tree that don't need c++ or cause regressions. Insignificant code cleanups. * plug-ins/common/poppler.c (load_dialog): display title of pdf at the top of the dialog, and show the page labels in the page selector. The loop for the page labels might be profitably moved into another thread, but I haven't actually timed how long it takes to be sure.