[Pkg-gmagick-im-team] Bug#868184: retitle

[Bastien ROUCARIÈS]

control: clone -1 -2
control: clone -1 -3
control: retitle -1 CVE-2017-11166 memory exhaustion in ReadTGAImage
control: retitle -2 CVE-2017-11170  memory exhaustion in ReadXWDImage
control: retitle -3 CVE-2017-11188 memory exhaustion in ReadMATImage 

CVE-2017-11188:
https://github.com/ImageMagick/ImageMagick/issues/509
is already filled

Fill remaining bug