DNG support and gsettings enabled pixbuf loader

• support handling DNG
• gdk-pixbuf loader uses gsettings for user persistent values (scaling, convert srgb, ..)
• support exiv2 0.28.x api changes

EoM/EoG cleanup

Introduce EoM plugin along side long standing EoG plugin

bug fix release

• support ImageMagick 7.x builds
• allow user to specify font (workaround for Fedora 26+ font issue #4)

cleanup/bug fix

• use smaller (1600) preview image for display by default - no point scaling fullsized preview images; can be overriden

OpenMP enabled

internal resize operations can be threaded via ImageMagick's OpenMP calls

scaling bug fix

v1.2.3.1

bug fix - scaling considers height as candidate for geometry

general use release

• ICC sRGB conversions
• image orientation/rotation
• memory/object optimisation and cleanup

ICC sRGB conversions optmisations

additional checks around embedded profiles to ensure sRGB conversion occurs when necessary

dupl code cleanup

v1.2.1

clean up debug logger, use variadic tmpl

memory optimisations

reduce needless use of Exiv2::image objs when the image is ready