[DP-64] Split out common data structures

[qnikst]

[Imported from JIRA. Reported by Tim Watson [Administrator] @hyperthunk) as DP-64 on 2013-02-01 08:44:42]
There are some very useful data structures which are currently internal to d-p. I would like to use some of these elsewhere, e.g., WeakTQueue in DPP, but I'd also like to stop exposing the internal modules which we currently do.

So, I think a separate package for common, shared modules such as data structures, would be a good idea. The big question is, what to call it... Hmn.