ADDED: New command sweeprolog-insert-term-with-holes

ADDED: New command sweeprolog-insert-term-with-holes

* sweep.pl (sweep_format_term/2, sweep_current_functors/2): new
predicates.
* sweeprolog.el (sweeprolog-read-functor-history): new variable,
history list for...
(sweeprolog-read-functor): new function.
(sweeprolog-forward-hole-repeat-mode): rename to...
(sweeprolog-forward-hole-repeat-map): corrected name for keymap.
(sweeprolog-analyze-end-font-lock): don't rely on
sweeprolog--next-hole to move point.
(sweeprolog-at-hole-p, sweeprolog-beginning-of-hole)
(sweeprolog-end-of-hole): new functions, used by...
(sweeprolog--previous-hole, sweeprolog--next-hole): revise.
(sweeprolog--precedence-at-point): new function, used by...
(sweeprolog-insert-term-with-holes): new command.
(sweeprolog-mode-map): bind it to C-c C-m
* sweeprolog-tests: test it.
* README.org ("Filling Holes"): move to top and rename to...
("Holes"): document sweeprolog-insert-term-with-holes.