Rename -fork to -decision

Altered items:
kbd-macro-decision, kbd-macro-decision-menu
Remove 'command and 'sexp options, add 'new option.

'command and 'sexp are redundant since they can be achieved with 'edit.
'new option is for defining new macro/branch on the fly.

Altered items:
kbd-macro-decision, kbd-macro-decision-menu
New function kmacro-cycle-ring-previous-undisturb

Need this to cycle the kmacro-ring without altering the calling macro

Altered items:
kbd-macro-decision, kmacro-cycle-ring-previous-undisturb,
kbd-macro-decision-menu