Revisions: Can't restore the first post revision

[ocean90]

Steps to reproduce:

• Create a new post with content
• Save the post
• Add some new content and save the post again
• Go to the revsions page by clicking on the link in the revisions metabox

What I get: ​http://cl.ly/Nwil

What I want: A button to the restore the first post revision.

[adamsilverstein]

will correct!

[adamsilverstein]

fixes

[adamsilverstein]

23898.diff​​

• corrects revision meta box list was removing oldest, not newest (now current) revision, clicking a single revision now takes you to that revision, current revision is not shown in list (but could be added)
• create a new post, make a single update, click update in revisions list, links to correct revision
• compare two mode available with two or more revisions
• corrects issue where handles were off by one in compare two mode

[markjaquith]

In 23872:

Make sure the first revision is seen as coming from emptiness, so it can be restored.

props adamsilverstein. fixes #23898.