[poppler] Poppler 0.53.0 released

[Albert Astals Cid]

Available from
http://poppler.freedesktop.org/poppler-0.53.0.tar.xz

Changes against 0.52.0 include:
 core:
  * Form support improvements
  * SplashOutputDev: Fix memory leak when rendering images with colormap and 
matte color
  * Minor fix in GlobalParams documentation

 qt5:
  * Expose form calculate order
  * Expose Form additional actions

 utils:
  * pdfimages: support 16bpc png and tiff images. Bug #99988
  * pdftohtml: fix small memory leak when constructing some filenames
  * pdfinfo: fix leak when printing JS

 build sytem:
  * Compile in C++11 mode

Testing, patches and bug reports welcome.

Cheers,
  Albert