Add serialization version to image and archive edit sessions

src/packages/archive-view/lib/archive-edit-session.coffee

@@ -7,6 +7,7 @@ File = require 'file'
 module.exports=
 class ArchiveEditSession
   registerDeserializer(this)
+  @version: 1
 
   @activate: ->
     Project = require 'project'

src/packages/image-view/lib/image-edit-session.coffee

@@ -8,6 +8,7 @@ _ = require 'underscore'
 module.exports=
 class ImageEditSession
   registerDeserializer(this)
+  @version: 1
 
   @activate: ->
     # Files with these extensions will be opened as images