starting implementation of grammar-v2.1, tipiQuestionnaire Deserialization from JSON
change in FirstLaunch deserializer, tipi as a single question with multiple subquestions
adding type=Slider in details for TipiQuestionnaire Deserializer
changing version to 2.1 in app
Merge tag '0.15.1' into develop

`schedulingMinDelay` and `schedulingMeanDelay` were ignored in parameters.
Typos in profile test scripts
merge develop to grammarv2.1 feature branch, fix conflicts
change ExpId to backendExpId
change naming of variables to be extracted from grammar json and access methods
change extraction method to match variable names as defined in grammar-v2.1
define classes that match exactly the grammar structure
adding Deserializers for TipiQuestionnaire and FirstLaunch
adding Deserializers
minor: local variable name refactoring
remove parameters declarations, now externalized in json
continuing Extraction of grammarv2.1 parameters from json
function to extract a standard Question object from TipiQuestionnaire extracted from json
changes in classes and functions previously calling hardcoded info in ServerConfig, now reading from sharedpredference object
removing unnecessary comments
changing the firstlaunch ordering along with the statusmanager flags (setting questionnaire or firstlaunch to completed) > build error at the moment