* Strip nils from collections on JSON and XML posts. [CVE-2013-0155] * dealing with empty hashes. Thanks Damien Mathieu

Conflicts:
	actionpack/CHANGELOG.md
	activerecord/CHANGELOG.md

Conflicts:
	actionpack/CHANGELOG.md
	activerecord/CHANGELOG.md
	activerecord/lib/active_record/relation/predicate_builder.rb
CVE-2013-0156: Safe XML params parsing. Doesn't allow symbols or yaml.