Builtin JSON support and ES5 functions

#### Array.prototype ####
* indexOf(value)
* lastIndexOf(value)
* every(callback)
* some(callback)
* forEach(callback)
* map(callback)
* filter(callback)
* reduce(callback[, initialValue])
* reduceRight(callback[, initialValue])

#### JSON ####
* JSON.stringify(obj [, replacer [, space]])
* JSON.parse(string)

#### Object ####
* Object.keys(obj)
* Object.getOwnPropertyNames(obj)
* Object.seal(obj)
* Object.freeze(obj)

#### String.prototype ####
 * trim()
 * trimRight() (Mozilla extension, not ECMAScript 5)
 * trimLeft() (Mozilla extension, not ECMAScript 5)