Include *all* pytz zone names, not just "common" ones.

Fix one fragile doctest, band-aid another.

lib/python/DateTime/DateTime.py

@@ -1848,5 +1848,5 @@ class strftimeFormatter:
 # Module methods
 def Timezones():
     """Return the list of recognized timezone names"""
-    return list(PytzCache._zlst)
+    return sorted(list(PytzCache._zmap.values()))
 

lib/python/DateTime/DateTime.txt

@@ -11,9 +11,15 @@ Function Timezones()
 Returns the list of recognized timezone names:
 
   >>> from DateTime import Timezones
-  >>> Timezones() # doctest: +ELLIPSIS
-  [...'Brazil/Acre'... 'Brazil/DeNoronha'... 'IDLE'... 'NZST'...]
+  >>> zones = set(Timezones())
 
+Almost all of the standard pytz timezones are included, with the exception
+of some commonly-used but ambiguous abbreviations, where historical Zope
+usage conflicts with the name used by pytz:
+
+  >>> import pytz
+  >>> [x for x in pytz.all_timezones if x not in zones]
+  ['CET', 'EET', 'EST', 'MET', 'MST', 'WET']
 
 Class DateTime
 ==============

lib/python/DateTime/pytz.txt

@@ -132,7 +132,7 @@ The _zidx attribute is a list of lower-case and possibly abbreviated
 time zone names that can be mapped to offical zone names.
 
     >>> cache._zidx #doctest: +ELLIPSIS
-    ['australia/yancowinna'... 'gmt+0500'... 'europe/isle_of_man'...]
+    [... 'australia/yancowinna'... 'gmt+0500'... 'europe/isle_of_man'...]
 
 Note that there are more items in _zidx than in _zlst since there are
 multiple names for some time zones.