Re #36; differentiate nested invalid values
Merge branch 'master' into issue-36

Conflicts:
	lib/active_interaction/filters/hash_filter.rb
Extract error arguments into helper function
Avoid unnecessary assignment
Add a test for InvalidNestedValueError
Merge branch 'master' into issue-36
Document InvalidNestedValueError
Rename "f" to "clean_value"
Update changelog
Use better names for error attributes
Merge branch 'issue-36'