db preconditons were added (in 1.1)

Created by: AnnaZagorski

Added some precondition tests like no misspellings in substance_names, if each annual_load has an id, facility_id, year and compartment and if these has null values. Further db_preconditions checks are if the compartments are unique and if the releases_data are given in kg/a. Furthermore interactive plots for the boxplots were added (with zooming option and save the graph with a mouse click)