Minimal fix for #885: Animations don't work in IE11

[wagich]

Checklist

• Have you linked to relevant open issues?:
  Animations do not work in ie11 #885
• I agree for this to be covered by the Velocity license?:
  Yes, I agree

Please describe this Pull Request in as much detail as possible:

As stated in #885, there is a problem running animations in IE11. I traced it to the utility function getValue, which tries to iterate arguments. This works in browsers with proper iterator support, but falls apart otherwise. The problem lies in arguments being of type object and not array so we can't really polyfill it (see babel/babel#1181).

With this PR, the args variable is iterated instead, since it is a proper array and can be polyfilled. The args-array is created and filled anyway

velocity/velocity.es5.js

Lines 150 to 152 in e238e87

	for (var _len = arguments.length, args = Array(_len), _key = 0; _key < _len; _key++) {
	args[_key] = arguments[_key];
	}

so this should be of minimal impact.

People who contributed to this change:

Michael Wagner

[wagich]

To add: you still need to polyfill everything that IE11 doesn't support natively – it's just that it is now possible to run using the appropriate polyfills instead of not at all.

[Rycochet]

I can't say when I'll have time to do this, but this is a good start for the problem - will see if I can get an automatic legacy build in for the polyfills at the same time...

[vojty]

spent few hours debugging before I found this :/ could you please release new version @Rycochet ?

[Rycochet]

@vojty I want to - but after merging this I started to update to the latest Typescript, and found quite a few potential bugs on the way - then ran out of time with it again - will try to finish the update and get things out this weekend!

[Rycochet]

@vojty Pushed a new version today, planning to do some work on it over the weekend, so hopefully the other issues get fixed too!