Add check for attr_protected bypass

CVE-2013-0276
Test examples of serialized attributes
Add check for serialized attributes vulnerability

CVE-2013-0277
Tests for CVE-2013-0277
Fix warning message in test for CVE-2013-0276
Merge branch 'master' into CVE-2013-0276_and_0277

Conflicts:
	test/tests/test_rails2.rb
	test/tests/test_rails3.rb
Add check for JSON parse vuln CVE-2013-0269
Add tests for JSON vulnerability
Merge pull request #262 from presidentbeef/CVE-2013-0276_and_0277

Checks for CVE-2013-02{69, 76, 77}