Fixes #477

Fix case sentitive error on test/built-ins/Object folder

Fixes gh-482

Tests for ES2015/2016 Completion Reform

Stop test262 from hanging Spidermonkey with an unimportant error message

The ES2016 draft further refines the completion values for `if` and
`with` statements. Two tests must be removed outright because the
completion value in those cases is no longer accessible from the
runtime.

In order to facilitate proper tail calls, ES2015 modified the completion
value of a number of statements.

These tests use `eval` to verify the new values.

Basic coverage for the %TypedArray% object

Replace a ES2015 test where calling the TypedArray constructor with
a floating number triggered a RangeError. Within the ES2016 specs,
the same call will trigger a TypeError, as the result for
`SameValue(NewTarget, here)` will be checked before.

Add tests for iterator expression in ForIn/Of head

Remove files that tested both PerformPromiseThen and
PromiseResolveFunction in favor of new tests that test
PromiseResolveFunction more directly and completely.

Update README.md

Although the `for..in` statement allows Expressions to define the
iterator, only an AssignmentExpression may occupy this position in the
`for..of` statement.

Improve Promise coverage: PerformPromiseAll & PeformPromiseRace

Coverage for length and name function properties

Note: Already uses the updated DataView function lengths from tc39/ecma262#266 (ES2016 Draft 2015-12-20)

Subclassing built-in objects

Improve Promise coverage: NewPromiseCapability

Improve Promise coverage: Promise Reject Function

Improve Promise coverage: Promise.prototype.then

Destructuring Binding - syntax and simple initialization

Add tests for instanceof operator when prototype property is primitive or getter

Object.{values,entries} tests