Miscelaneous fixes and changes:

Fix return for dep_table_has_selectorcol in Config::Screen.pm;
Do screen_store_key_values only if there is a TM with selectorcol;
Add an experimental update_or_insert method in Model.pm;
Add feature in data_read in TM to also return the selectorcol value;
Fix templdet.conf, the screen/style is required;
Refactor TemplDet (again) use TM widget;