Adds number_of_semester to Search
Adds number_of_semesters (for A) to Search
Adds grade to Search
Adds federal_state_name to Search
Merge branch 'master' of https://github.com/Datenbankpraktikum2013/Datenvisualisierung
Adds semester_of_matriculation to Searches
Adds semester_of_deregistration to Searches
Merge branch 'master' of https://github.com/Datenbankpraktikum2013/Datenvisualisierung