Use fetch for sentinel_value

Use DateTime for sentinel_value example

Use an epoch. rails convers '0' or 0 to nil for datetime fields

Add test for restore

Update readme

Move MYSQL note to bottom of readme

update destroyed? for sentinel value

This reverts commit 566b1cbd.

Conflicts:
	README.md
	test/paranoia_test.rb

Fixes #149

Fixes #148

Fixes #143

Fixes #138

Removed deprecated assert_nothing_raised from test.

Fixes #117

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

Fixes #119

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

Fixes #104

Fixes #95

As per #92

Fixes #91

Fixes #81
Fixes #84

Conflicts:
	lib/paranoia.rb

Update/save callbacks should not be called at all during a destroy call, as would happen with the code from that PR.

References: https://github.com/goncalossilva/acts_as_paranoid

Fixes #76

Fixes #72

Modelled on AR::Relation.destroy

If you care about having objects frozen after calling destroy/delete, then please call freeze on that object manually.

Fixes #32