Partially fix 1678141: add an int to ColorAccumulator converter, same as the Color one
drwxr-xr-x - ETL
drwxr-xr-x - autobuild
drwxr-xr-x - gtkmm-osx
drwxr-xr-x - synfig-core
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drwxr-xr-x - synfig-osx
drwxr-xr-x - synfig-studio