Rewrote Dashtap function 'setread'.

* Reordered argument somewhat to make them unambiguous.

* Now accepts input as argument, as well as on standard input.
Rewrote Dashtap function 'seteval'.

* Reordered argument somewhat to make them unambiguous, and analogous to
  'setread'.
Cosmetic change of documentation comments.
Added Dashtap functions 'title' & 'end_title'.

* 'title' works similar to 'note', except that the last title is also
  output as a diagnostic when a test fails.

* Added tests for new functions 'title' and 'end_title'.