Changes for Date::Set::Timezone - Timezone/DST code for Date::Set

 0.01_04 
    - added a test from Martijn van Beers (and got an error)
    - tz() doesn't change $self
 0.01_05
    -  make a 'package'
 0.01_06
    - inherits Date::Set
 0.01_07
    - utc_string
 0.01_08
    - utc_string finished
 0.01_09
    - utc_string renamed tz_string
    - Martijn's test works
 0.01_10
    - renamed _simple_utc_as_string to _simple_as_string
 0.01_11
    - more oo-like tests
    - print $set works
 0.01_12
    - tz() and tz_change are better defined
    - offset() works for days/months/years
 0.01_13
    - quantize()
    - the $self->{cant_cleanup} property is preserved across tz changes
 0.01_14
    - quantize() tests
 0.01_15
    - recur_by_rule started
 0.01_16
    - recur_by_rule normalizes parameters to $self timezone
 0.01_17
    - recur_by_rule removed ! Date::Set::recur_by_rule works better.
 0.01_18
    - POD
    - tests
 0.01_19, 0.01_20
    - more tests
 0.01_21
    - changed test offset to +02/+03
 0.01_22
    - better test sequence for DST start/end
 0.01_23
    - tests
    - found _simple_spaceship() bug in Set::Infinite::_Simple.pm
 0.01_24
    - pass DST start/end tests
 0.01_25
    - rrule with 'local time' hours
    - documented 'utc' option (although it is not implemented yet)
 0.01_26
    - added 'weeks' to 'utc'=>0 defaults
 0.01_27
    - finished 'utc=>0' code
    - added 'hours' and 'weekdays' to default 'utc=>0' in order to make RRULE work
      this actually changes default 'utc' behaviour to zero, since it doesn't make 
      diference for minutes or seconds units.
    - duration() now works in 'local time' mode only, since it doesn't know about 'utc=>1'.
    - all tests pass
 0.01_28
    - split files
    - requires Set::Infinite v.0.39 - correction in spaceship()
 0.02
    - tar.gz packaging
 0.02_01
    - timezone without name doesn't print with 'space'
 0.02_02
    - 'until' works
 0.02_03
    - added tests for dst with DTSTART
 0.03_01
    - Date::ICal methods are accessible through AUTOLOAD
 0.03_02
    - better stringification. Understands the difference between
      'floating time' and 'UTC'; prints long timezone names with ';'
      instead of space (just because it looks better).
    - all Date::ICal objects are 'floating time' by default;
      new() generates only floating times (instead of UTC).
      (actually, new() is broken, because it doesn't change
      it's data when it inherits a timezone)
    - include 'release notes' in POD
    - document 'floating time' vs UTC problems
0.03_03
    - tz_change does not change floating times.
      (breaks some tests!)
0.03_04
    - new() fixed -- changes it's data when it inherits a timezone
    - some tests fixed
    (some debug code added)
0.03_05
    - fixed dst in _tz_change (uses {dst_utc}, then {dst})
0.03_06
    - some internal error in @{ $self->{list} }
0.03_07
    - union() works with floating times.
    - most tests fail, due to new union() behaviour
0.03_08
    - union() tests ok
    - fixed a bug in Set::Infinite::copy
0.03_09
    - all methods accept mixing tz-times and floating-times
0.03_10
    - remove utc=>1 option (quantize/offset)
0.03_11
    - tz(), tz_change() accept recurrences
0.03_12
    - documentation
    - tz has an internal 'id'
    - performs less internal tz conversions (tests run 4s -> 1.8s)
0.03_14
    - uses 'dst cache' (tests run in 0.8s)
    - as_string doesn't show timezone for "inf"
0.03_15
    - use separators() instead of @separators
0.04
    - upgrade Makefile.PL dependencies
