[dev] New Wiki diff funcionality.

[eculp at encontacto.net]

Chuck,

The new wiki diff funcionaltiy is great.  I just gave it a test
drive.  I took the default page and modified it.   The history
woked fine I selected the 1.0 to 1.0 diff and it showed no
changes as expected, the 1.0 to 1.1 worked flawlessly.

I then went back and tried to make another change to have a third
version to play with and when I tried to save it, I got

  History page not found
  Page Saved

at the top of the screen and the changes were not saved.  I then
decided to check the history that hadn't changed and tested the
1.1 to 1.1 diff and got

Fatal error: Call to a member function on a non-object in
/usr/local/www/data/horde/wicked/diff.php on line 21

Maybe they are related errors.  Plus, I shouldn't really expect a
result for the diff from 1.1 to 1.1, the diff option for the
current version may not need a select button, I don't know.

Thanks again for this addition.  I think that it really makes
wicked much more usable for many of us.

ed