Parcelable operation result with logging capabilities + import logging

This is the first step towards closing the closing of #530

What's missing is a way to display this to the user, it just gets output to logcat (for debugging purposes). I'll be looking into a way to unintrusively display this information, or operation results in general, to the user. A possible outcome of this is switching from the AppMsg library to [SuperToasts](https://github.com/JohnPersano/SuperToasts), but I'm not sure yet.

On the long run, other complex operations should create a log and return them in the parcel, too. The OperationResultParcel is sufficiently generic for that.