Add failing spec for #69.
Fix #69: regression, multiple property assignments in Trash.

Heavily inspired from https://github.com/intridea/hashie/commit/9a389853c98af876a80d1914acc0e24c4084ffb3.
Preserve backward-compatible translations when a single property is translated.
Add pry and pry-stack_explorer for debugging
Merge pull request #212 from dblock/69-multiple-properties-in-trash

Fix #69: multiple property assignments in Trash.
Merge pull request #213 from michaelherold/add-some-debugging-tools

Add pry and pry-stack_explorer for debugging
Fix: working guard.