Fixed multiple issues with textual Pager:
- First line of output was not being displayed (off by one error).
- SetLines was being ignored. Page size was fixed to terminal size.
- Only every 2nd 'enter' key was registered by tty.read, switched to using 'n' key instead.
- Prompt string did not truncate on narrow terminals
- Added paging support for MS Windows terminals
- Pager no longer exits automatically at end of buffer
- Fixes day-one issue of non displaying empty lines
- Correctly handles files smaller than the terminal