much saner prototype syntax

I think I got confused once when I did `x = foo` and it was being
shared between instances. Silly me, it should have been `x: foo`.

This CoffeeScript thing...

h/js/src/controllers.coffee

 class Hypothesis extends Annotator
-  # Annotator state variables.
-  this::bucket = -1     # * The index of the bucket shown in the summary view
-  this::detail = false  # * Whether the viewer shows a summary or detail listing
-  this::hash = -1       # * cheap UUID :cake:
-  this::cache = {}      # * object cache
-  this::visible = false # * Whether the sidebar is visible
-
   # Plugin configuration
   options:
     Heatmap: {}
@@ -14,6 +7,13 @@ class Hypothesis extends Annotator
       showViewPermissionsCheckbox: false,
       userString: (user) -> user.replace(/^acct:(.+)@(.+)$/, '$1 on $2')
 
+  # Internal state
+  bucket: -1      # * The index of the bucket shown in the summary view
+  detail: false   # * Whether the viewer shows a summary or detail listing
+  hash: -1        # * cheap UUID :cake:
+  cache: {}       # * object cache
+  visible: false  # * Whether the sidebar is visible
+
   this.$inject = ['$rootElement', '$scope', '$compile', '$http']
   constructor: (@element, @scope, @compile, @http) ->
     super @element, @options