Use a spec-compliant polyfill for bind

Casper's prototype was not compliant (see n1k0/casperjs#631). While this is
fixed in Casper latest, it's an issue in older versions.

So, use mozilla's polyfill.
Play nice with Casper > v1.0.2

- Call patchRequire for Casper > v1.0.2
- Fix hello example to work with recent Caspers
- Fix tests to work with old and new casper require

Thanks to @rumca and @ucarbehlul for helping me run this one down.

close #73
close #75