Diverse Code Cleanups

*Code wurde PEP-8 gerecht formatiert
* Kleine Fehler die der PyCharm Inspector beanstandet wurden korrigiert

utils/icalendar/prop.py

@@ -653,17 +653,17 @@ class vDDDLists:
         self.dts = vDDD
 
     def ical(self):
-        '''
+        """
         Generates the text string in the iCalendar format.
-        '''
+        """
         dts_ical = [dt.ical() for dt in self.dts]
         return ",".join(dts_ical)
 
     def from_ical(ical):
-        '''
+        """
         Parses the list of data formats from ical text format.
         @param ical: ical text format
-        '''
+        """
         out = []
         ical_dates = ical.split(",")
         for ical_dt in ical_dates: