corrected errors from previous commit (404)
Bug fixing and improvements

- fixed bug due to registry singleton instance passed when not necessary
- added field translations and supported field_labels as in admin table
Merge branch 'admintable-export-fix' into develop
implemented a mobile layer
Now mobile devices are detected and if mobile site setting is set to
true (and no other conditions are implemented in the core class),
site templates, modules templates and all css are searched for a
mobile version to load
Merge branch 'mobile-themes' into develop