Fix: Remove polyfill

[timfish]

Removes the need to polyfill Number.parseInt|parseFloat by simply using the top level parseInt|parseFloat.

Fixes #162

[coveralls]

Coverage increased (+0.3%) to 97.531% when pulling 99dcddd on timfish:master into 65c39be on NaturalIntelligence:master.

[amitguptagwl]

Sorry I didn't understand that how are you ensuring it to work on IE?

[timfish]

I changed Number.parseFloat to simply use parseFloat. parseFloat exists even on IE6.

[amitguptagwl]

We knowingly placed them to fix an error when we found them not present in some browser. You can probably check in closed issues for more detail.

[timfish]

I don't think you've understood my changes correctly.

Number.parseInt does not exist in older versions of IE.

To fix this, it looks like a polyfill was added which copies parseInt from global window Number.parseInt = window.parseInt.

But the above polyfill has mistakes in it. #162 highlights this. window does not exist in all JavaScript contexts.

Rather than use Number.parseInt you should just be using parseInt on its own which works in every browser released in the lat 10 years.

This PR fixed the issue with window and still works in every browser.

For best browser support, you should be using parseInt over window.parseInt or Number.parseInt

[amitguptagwl]

I'm fine with having in this case

if (!Number.parseInt) {
  Number.parseInt = parseInt;
}
if (!Number.parseFloat) {
  Number.parseFloat = parseFloat;
}