[poppler] Poppler 0.26.3 released

[Albert Astals Cid]

Available from
http://poppler.freedesktop.org/poppler-0.26.3.tar.xz

qt5:
 * autoconf: Improve moc-qt5 detection
 * Fix compilation with MinGW

glib:
 * Fix typo in api docs
 * use C90-style comments in public headers

core:
 * Error out instead of exiting if allInter grows too much. Bug #78714

qt4:
 * Update required version to Qt 4.7.0

build system:
 * Include stdio.h from poppler-config.h

misc:
 * Update .gitignore files

Cheers,
  Albert