Order of no particular importance:

Core:
* Add a queing API
* Add a way to import GPG keys
* Split up PolicyKit install into different types
* Add files in package into Description signal
* Add package size into description signal
* Valgrind everything
* Add GetPercentage and GetSubPercentage for coldplugging

Backends:
* Add conary backend
* Dummy backend should use subpercent and install deps
* Add enough new error enums for all the backends