Updates are fetched from http://gmic.sourceforge.net/updateXXXX.gmic
where XXXX is curent gmic version. So now it is update1590.gmic

* compile gmic with zlib dependency, needed to extract update
  file from cimgz format
* implement merging of two gmic file definitions,
  if second file has same filter in same category,
  its definition will be overwritten
* applicator has to pass *.gmic definitions to gmic so that user
  defined filters work
* No need to use KisImageLayerAddCommand to add paint layer