Fix issue with sha1 computation in QtCreator in some context (run without debug on Linux)

Signed-off-by: Christophe Chapuis <chris.chapuis@gmail.com>
Remove some debug traces

Signed-off-by: Christophe Chapuis <chris.chapuis@gmail.com>
UI improvements:
 - Display of collection contents based on a flickable Flow, to have less structure in the display of the collections. Still needs some refinement.
 - Rework of the "current path" display: use an horizontal flickable list to display the path elements, in order to handle possible long paths

Signed-off-by: Christophe Chapuis <chris.chapuis@gmail.com>