Fix for #44: Don't store bindings in the  BindingIndex unless they have a canonical binding present
Added note to CHANGELOG
Merge pull request #45 from fancyremarker/garnered-find-fix

Fix for #44: Don't store bindings in the  BindingIndex unless they have a canonical binding present
Added :invalidate_mongoid_root option

This ensures that a root document's bound caches are invalidated along with
any embedded document.
Add README note
Merge pull request #46 from fancyremarker/root-document-invalidation

Added :invalidate_mongoid_root option
Prepare for 0.4.3 release