Add version to doc manifest

Ref #25.

assets/javascripts/models/doc.coffee

@@ -1,10 +1,10 @@
 class app.models.Doc extends app.Model
-  # Attributes: name, slug, type, release, db_size, mtime, links
+  # Attributes: name, slug, type, version, release, db_size, mtime, links
 
   constructor: ->
     super
     @reset @
-    [@slug_without_version, @version] = @slug.split('~v')
+    @slug_without_version = @slug.split('~v')[0]
     @fullName = "#{@name}" + if @version then " #{@version}" else ''
     @icon = @slug_without_version
     @text = @toEntry().text

lib/docs/core/doc.rb

@@ -66,6 +66,7 @@ module Docs
       def as_json
         json = { name: name, slug: slug, type: type }
         json[:links] = links if links.present?
+        json[:version] = version if version.present?
         json[:release] = release if release.present?
         json
       end

test/lib/docs/core/doc_test.rb

@@ -133,10 +133,10 @@ class DocsDocTest < MiniTest::Spec
       assert_instance_of Hash, doc.as_json
     end
 
-    it "includes the doc's name, slug, type, and release" do
+    it "includes the doc's name, slug, type, version, and release" do
       assert_equal %i(name slug type), doc.as_json.keys
 
-      %w(name slug type release links).each do |attribute|
+      %w(name slug type version release links).each do |attribute|
         eval "stub(doc).#{attribute} { attribute }"
         assert_equal attribute, doc.as_json[attribute.to_sym]
       end