fix composer user app template and allow minimal composer specs

I needed to  add phpdir to the file attr to pass the json file to the dep generator. negative side effect: now the prov gen parses also the json file and trys to create provides. This doesn't make much sense for non libraries. Maybe we should split up the 2 generators into separate files (i.e. composer-req.attr composer-prov,attr etc...) and handle each generator individually?