Added more performance tests

Apparently the fastest way to do it (after plain call to method) is via
prototypical methods `on()` and `set()`:

Move via event listener x 4,000 ops/sec ±0.87% (94 runs sampled)
Direct call obj.setAttributeNS() x 4,566 ops/sec ±0.75% (96 runs sampled)

Property getter and setter are the slowest ones:

Move via property x 768 ops/sec ±1.38% (91 runs sampled)
Move via bound property x 818 ops/sec ±0.94% (89 runs sampled)
Merge branch 'master' of github.com:anvaka/jsbind