Refactor Console

* Move all the code to Console module.
* Make a base abstract class and separate implementations for different
  systems. This fixes a wrong encoding in console on Linux.
* Make global `console` methods which is available in all files where
  console.rb is included by `require`.
Fix checking page content due to changed page DOM

Now <p> doesn't contain <span>s with id "text2" and "textDate" and
contains `<span>[title:]</span> [date]`