Any reason why you're building dictionaries throughout the code using `dict()`? @mtomwing brought it up earlier: https://github.com/Freeseer/freeseer/pull/402#discussion_r7994196

Using `{ ... }` is [more efficient](http://doughellmann.com/2012/11/the-performance-impact-of-using-dict-instead-of-in-cpython-2-7-2.html) and IMO also cleaner. I think the constructor makes more sense if you're passing it an iterable of key-value pairs.