bug#4307: 23.1; vc-annotate should run svn asynchronously

[Dan Nicolaescu]

Tom Tromey <tromey@redhat.com> writes:

  > Please write in English if possible, because the Emacs maintainers
  > usually do not have translators to read other languages for them.
  > 
  > Your bug report will be posted to the bug-gnu-emacs@gnu.org mailing list,
  > and to the gnu.emacs.bug news group.
  > 
  > Please describe exactly what actions triggered the bug
  > and the precise symptoms of the bug:
  > 
  > 
  > I typed "C-x v g" (vc-annotate) in a buffer in a source tree managed by
  > svn.
  > 
  > I expected "svn annotate" to run asynchronously.  This is what happens
  > for CVS.  Instead, it ran sychronously.

If you want to work on this, just replace the " 0 " in
vc-svn-annotate-command with " 'async ".

Looking at the other backends, it looks like vc-mtn.el needs the same
treatment.

vc-bzr.el and vc-hg.el need that, plus the rest of their corresponding
vc-*-annotate-command functions needs to be moved inside a
`vc-exec-after'.