Fixes #1447 (and see also #1451, #1452) by making undo pending edits be just a button on the display package page. Not a separate page.

Conflicts:
	src/NuGetGallery/PackagesController.generated.cs
Merge pull request #1546 from NuGet/tilovell/1447-MakeUndoPendingEditsASimpleButton

Tilovell/1447 make undo pending edits a simple button