[ES3 compat] Make the test lagacy IE compatible.
[ES3 compat] Work on legacy IE: Object.freeze().
[ES3 compat] Work on legacy IE: global export.
[ES3 compat] Work on legacy IE: Array.prototype.indexOf.
Merge pull request #16 from saneyuki/es3

Enable to work on legacy IE6~8.
In the future release, we'll remove to support them ABSOLUTELY.