Fix #19.  Use apply instead of call proxy trap.
Fix #17.  Use let and destructuring in iterator example.
Fix #27.  Add binary and octal constants.
Make binary/octal literal example less confusing

`0b111110111 === 0o767 === 503 === 0x1F7` might not be the best example to demonstrate these features. The intention might be clear, but in JavaScript this statement evaluates to `false`. Let’s avoid the confusion.
Merge pull request #29 from mathiasbynens/patch-1

Make binary/octal literal example less confusing
Remove hex literal example since this is not new.
Add binary and octal literals to TOC
Fix some typos