bug#14398: 24.3.50; Customize: `Revert...' and `Apply'

[Drew Adams]

Haven't tried it, but the patch looks great.

I especially appreciate the fact that you adding
a missing doc string.  Thx.
___

FWIW -

I'll incorporate those changes into my library
`cus-edit+.el', which adds these three items to
`custom-commands': `Consider Unchanged', `Ignore
Unsaved Changes', and `Set from External Changes'.

The help strings for those 3 are:

"Treat changed preferences as if they were
unchanged, without saving them"

"Add to the `customize-unsaved-ignore' preferences,
whose changes are ignored by `customize-unsaved'"

"Tell Customize that all preferences changed
outside it are now set"

(Tried to interest Emacs in these, to no avail.)