remove rexml security fix for rubies 1.8

 change Log

This reverts commit 76f0fa60, reversing
changes made to 28cd098d.

a prompt string in include_blank option for date helpers

If you used dynamic constraint like that:

  scope :constraint => MyConstraint.new do
    mount RackApp => "/foo"
  end

routes were not displayed correctly when using `rake routes`.
This commit fixes it. If you want nice display of dynamic
constraints in `rake routes` output, please just override
to_s method in your constraint's class.

remove File#to_path alias

Test::Unit::Util::BacktraceFilter not available in ruby19 test/unit

AS::Callbacks: improved __define_runner performance

::BasicObject always defined in ruby 19

ruby 1.9 returns method names as symbols

Module#name returns nil for anonymous class in ruby 1.9

remove date methods that are present in 1.9 ruby

remove useless 1.8 ruby code from Range#step

AS::Callbacks: improve __define_runner perfomance for non-keyed callbacks.

remove useless 1.8 ruby code from Range#step, because Range#step without block always returns enumerator

* Passing edge information to the views fixes the lack of the edge badge
and sets the appropriate welcome page on edgeguides.rubyonrails.org.
* Changes in the welcome message to hyper link the rails tree based on
the version.
* Mention the Amazon url from where kindlegen can be downloaded.

Fix my name in CHANGELOG.md