Improve UI

[stanier]

The Material Design UI currently does not follow design and layout principles as religiously as it should. The initial implementation of the UI library was more or less to "test the waters". Now that the decision has been made to keep it, elements should be aligned according to https://www.google.com/design/spec/material-design/. This takes a lower priority to core functionality and will be done lazily until core features have been implemented and confirmed to work as intended.