printf -> error

Bug #81513
cairo: Make sure we always push a transparency group in setSoftMaskFromImageMask()

Because that's what unsetSoftMaskFromImageMask() assumes.

https://bugs.freedesktop.org/show_bug.cgi?id=81624
annots: Fix a crash when adding annot without contents

Having no content in an annotation results in a crash when generating
its appearance, since the contents pointer is dereferenced.
For consistency, the same has been done in Annot::initialize.
glib: Return NULL in poppler_annot_get_contents also for empty strings
glib: Fix a memory leak when getting text layout and attributes
Don't check for inlineImg twice

Bug #82059
Improve non-latin characters in inline notes

Preview commit had by mistake changes in these two files that belong here

Bug #65956
Make sure e is always initialized
Update (C) years
0.26.4
Cairo backend added to Qt4 wrapper
Setting default Qt4 backend to Cairo
Forcing subpixel rendering in Cairo backend
Enabling slight hinting in Cairo Backend

Originally suggested at:
http://bugs.freedesktop.org/show_bug.cgi?id=3307#c20