build: Fix gtk-doc building problem

https://bugzilla.gnome.org/show_bug.cgi?id=731061
Updated Norwegian bokmål translation.
Fix documented file formats, bug 731679
appdata: Add rudimentary appdata file

https://bugzilla.gnome.org/show_bug.cgi?id=708760
i18n: Add appdata file to POTFILES.in
appdata: Do not use the generic name in the software center

In GNOME3 Evince is a core module, so installed by default. We want to show the
project name in the software center so that it can be installed on other
desktops. This also means we don't get multiple "Document Viewer" items in the
search results that correspond to different projects.
Updated Slovenian translation
Updated Spanish translation