Fix timer

* Remove duration
proto.js: Array.from() should be simple polyfills
extendProperties() should be Object's custom extend property

* Add Object.extendProperties()
Rename Object.extendProperties() to Object.extend()
proto.js should be loaded at first
Rename proto.js to extend.js
extend.js: Fix IIFE's name(file's description)
camelCase() should be String.prototype's custom extend property

* Add String#toCamelCase()
* utils.js: Refine NCFTest creation
Refine `NCFTest` creation

`NCFTest` is `window`'s property.
Refactor `Test` Constructor

* Add String#toElement()
* Add Test#createFeatureList(), Test#getTest(), Test#addPassedSpecToSideList()
Introduce `Timer`, and use it
Rename `specs` to `specIDs`
Rename `spec` to `id`
Refine `Test` Constructor and `main()`
Rename specsTested to testedSpecs
Rename `addPassedSpecToSideList()` to `addTestedSpec()`
Refactor main.js about `Score` Constructor
Refine `Timer`

`Timer` should be Constructor.
Refine more main.js
Refactor main.js about `Test` Constructor

* Add Test#createSpecTest()