New `slime-trace-dialog-copy-down-to-repl' command.

* contrib/slime-trace-dialog.el (slime-trace-dialog-mode-map): Bind M-RET
to new `slime-trace-dialog-copy-down-to-repl'.
(slime-trace-dialog-copy-down-to-repl): New function, in-line with
slime-repl.el's functions.
(slime-trace-dialog--format-part): Two extra text properties to
find the trace part at point.

* contrib/swank-trace-dialog.lisp (find-trace-part): new exported
function.
(inspect-trace-part): rewrite in terms os FIND-TRACE-PART.
Simplify change of 41cc9eb: don't over-call SWANK on REPL calls.

* contrib/slime-repl.el (slime-repl-eval-string): simplify change of
2014-01-30; don't remotely call SWANK:SET-REPL-VARIABLES on
acknowledgement.

* contrib/swank-repl.lisp (set-repl-variables): Deleted.
(*repl-set-variables-function*): Deleted, not needed for now.
(repl-eval): Set *, + and / variables saved from last call just
before the EVAL-REGION that might use them.
Revert previous swank.asd change until proper ASDF support is built in.

See problems reported in #76 and and #83.

* swank.asd: revert previous change by 2014-01-05 Francois-Rene
Rideau until proper swank-loader-less ASDF support can be build
it. It exhibits problems on ABCL and SBCL.
Closes #101: don't use new Emacs 24.4's colon load-path in Makefile

* Makefile (LOAD_PATH): Closes #101: Don't use new : (colon)
feature of upcoming Emacs 24.4.