The variable is used in Detiq-T to copy translations files (*.qm)
to the 'lang' subfolder

... and update Detiq-T submodule

and improve messages, remove useless comments

And methods have been reordered in cpp file

Rename some variables
Remove unnecessary variables
Add missing letters in comments / strings
Add comments

The error is now stored in an Image with double values,
without restriction on these

Also update the lib to the last revision

This commit also update detiq-t submodule to the last commit

This allows quantification maps to apply on negative values