(calc-selection-cache-entry): Moved declaration to earlier in the

(calc-selection-cache-entry): Moved declaration to earlier in the
file.

(calc-selection-cache-num, calc-selection-cache-comp)
(calc-selection-cache-offset, calc-selection-true-num)
(calc-final-point-line, calc-final-point-column)
(calc-original-buffer): Declare them.

(calc-fnp-op, calc-fnp-num): New variables.
(calc-find-nth-part, calc-find-nth-part-rec)
(calc-select-previous): Replace op and num by declared variables.

(calc-rsf-old, calc-rsf-new): New variables.
(calc-replace-sub-formula, calc-replace-sub-formula-rec):
Replace variables old and new by declared variables.

(calc-sel-reselect): New variable.
(calc-auto-selection, calc-enter-selection, calc-edit-selection)
(calc-sel-evaluate, calc-sel-expand-formula, calc-sel-expand-formula)
(calc-sel-mult-both-sides, calc-sel-add-both-sides):  Replace variable
reselect with declared variable.

(calc-edit-disp-trail): Declare it.
(calc-finish-selection-edit):  Replace variable disp-trail by declared
variable.