enable Wikipedia support

Since wikipedia server is language specific we should first detect
language of the text by querying Google Translate. Make sure you have
access to both Google Translate and Wikipedia service to use this
function.

frontend/apps/reader/readerui.lua

@@ -29,6 +29,7 @@ local ReaderHighlight = require("apps/reader/modules/readerhighlight")
 local ReaderScreenshot = require("apps/reader/modules/readerscreenshot")
 local ReaderFrontLight = require("apps/reader/modules/readerfrontlight")
 local ReaderDictionary = require("apps/reader/modules/readerdictionary")
+local ReaderWikipedia = require("apps/reader/modules/readerwikipedia")
 local ReaderHyphenation = require("apps/reader/modules/readerhyphenation")
 local ReaderActivityIndicator = require("apps/reader/modules/readeractivityindicator")
 local ReaderLink = require("apps/reader/modules/readerlink")
@@ -142,6 +143,13 @@ function ReaderUI:init()
         ui = self,
         document = self.document,
     })
+    -- wikipedia
+    table.insert(self, ReaderWikipedia:new{
+        dialog = self.dialog,
+        view = self[1],
+        ui = self,
+        document = self.document,
+    })
     -- screenshot controller
     table.insert(self.active_widgets, ReaderScreenshot:new{
         dialog = self.dialog,