Allow for some additional post-processing

This commit makes the s:repeat function public as repeat#run to allow
manual remapping for customization.
Go back to using feedkeys()

Since there seems to be a bug with "norm" in Vim prior to 7.3.100,
better go back to using feedkeys.

The repeat call can still be remapped by using something like:

  nnoremap . :call repeat#run(v:count)<bar>call feedkeys('`.', 'n')<cr>
Documentation fix for repeat#setreg()

Need to :execute the :silent! call to avoid that the remainder of the
command line is aborted together with the call when repeat.vim is not
installed. Otherwise, <SID>MyFunction() won't be invoked, and the
mapping does nothing.
Allow customizing all mappings

f1d0fbbdf4d77b73ba47146bada375223b3d733a allowed customizing the .
mapping by making the implementation function publicly accessible. Let's
do the same to s:wrap(), so that the other mappings (u, U, <C-R>) can be
extended, too.

(Personally, I'd like to have undo / redo stop and beep at the last
saved position, to avoid that I accidentally undo beyond the saved state
even though I didn't intend to.)
repeat.vim 1.1

* Fix adding trailing spaces when 've' is not empty.
* Don't increment b:changedtick, offer invalidate instead.
* Support repetition with original register.
* Don't clobber existing U map.
* Respect 'foldopen' on undo.
* Allow customizing all mappings.
Merge https://github.com/tpope/vim-repeat

Conflicts:
	autoload/repeat.vim