Unclear logic for which offsets are _adjust_dst
The base class `DateOffset` has `_adjust_dst = False`.  Then almost every subclass overrides it to `True`.  The exceptions being: `BusinessHour`, `CustomBusinessHour`
`LastWeekOfMonth` (in contrast to `WeekOfMonth`, seems like a likely mistake)
`Tick` and subclasses.

The `Tick` classes make sense since those are glorified `Timedeltas`.  `BusinessHour` I could imagine being special because it is sub-daily, but I'd appreciate a confirmation that this is intentional.  `LastWeekofMonth` I suspect is a mistake.

I'll roll this into an existing issue and close once I get the lay of the land.
