- Fixed a number of deficiencies in the line wrapping.
- Fixed a bug where the page could scroll multiple times per keypress.
- Re-read terminal dimensions after user input, in case they
resized the terminal while we were waiting.
- Added an 'R' key to print the rest of the file without prompting.
- Crudely support tabs in the line-wrapping code by converting
them to 8 spaces.