Pass date object directly to arrow for consistent humanized dates

With the previous method of using arrow, the same date object would
result in different humanized dates. Apparently using now() and then
replacing the date components triggers some inaccuracy.

Simplify the call to arrow by passing it the datetime object directly.

topydo/lib/Utils.py

@@ -113,7 +113,5 @@ def translate_key_to_config(p_key):
 
 def humanize_date(p_datetime):
     """ Returns a relative date string from a datetime object. """
-    now = arrow.now()
-    date = now.replace(day=p_datetime.day, month=p_datetime.month, year=p_datetime.year)
-    return date.humanize().replace('just now', 'today')
+    return arrow.get(p_datetime).humanize().replace('just now', 'today')