simplify the way the tableview header works

tableview is so very annoying to use :(

- put header row into the model and theme the delegate accordingly
- throw away the manual row, it was incorrectly placed anyway
- throw away the layout code it is no longer necessary
- no longer elide the delegate we want scrollbars everywhere so we can
definitely fit all the data in the view
- space the columns using largespacing so they don't stick together
- use monospace font so the rwx shebang is aligned properly