better handling metadata defaults model values
better handling object model defaults values
better handling screen model defaults values
bug fix. addresses #54
bug fix. addresses #54
improve robustness when checking version
remove useless log and replace log by debug
catch and log exception in case of error
indent the update .dahu files properly
Ajout objet background
create specific object models depending on its type
add background view
add background view
Merge branch 'next-first-layout' of https://github.com/dahuapp/dahu into next-first-layout