really_destroy! and has_one associations

Fixes #149

Fixes #148

I am tired of supporting Rubinius. I don't use it, nor know of anyone who uses it. Every damn month it breaks on Travis in some new and brilliant way and I don't have the time or energy to support it.

If people truly care about it, then *they* can support it.

The `acts_as_paranoid` gem (v0.4.1) uses assignment followed by a call
to `#save` for restoring a record:

    # in #recover
    run_callbacks :recover do
      recover_dependent_associations(options[:recovery_window], options) if options[:recursive]

      self.paranoid_value = nil
      self.save
    end

This runs any `update` callbacks as well as `recover` callbacks.

Paranoia uses `#update_column` instead of `#save`, so no `update`
callbacks are run when restoring a record.

With this commit the difference in behavior is described in the section
"Acts As Paranoid Migration" of the README.

Fixes #134

Fixes #143

touch_paranoia_column before really_destroy!-ing a record in rails 4.1.x. reloading already really_destroy!-ed associations is needed, otherwise super.destroy! will try to destroy these asociations (because they still exist on the activerecord object, but are already removed from the database)

Fixes #143

FIX: reflections have been reworked in rails 4.1.2 - reflections is no longer available on activerecord objects, only on the class.

Fixes #143

Fixes #143

Update paranoia_test.rb

Fixes #138

Removed deprecated assert_nothing_raised from test.

💣

Fixes #117

Minor changes to make it more slightly readable

Fixes #126

Fixes #125

  * Based on partial fix by @stupergenius
  * Handles nil case for hasOne associations

Fixes #119

Fix `real_destroy!` typo in readme

Add index to deleted_at column in README

Rails normally returns the model on successful destroy and false if any
callback fails.

Fixes #104

Fixes #95

destroy! now once again calls destroy

This is because destroy! is called by :dependent => :destroy association definitions (yes, destroy! and not destroy), which means that associated records of a paranoid object would suddenly go missing... making it very hard to restore them!

So instead, it's now called really_destroy! and destroy! is just an alias for destroy once again

[ci skip]

Fixes #97

As per #92