Explicitly checked for 'undefined' bug

[nobelium]

I have gone through almost all the files in core, renderer, scene and dynamicscene..

if (!variable) --> if(typeof variable === 'undefined')
var a = a || b; --> var a = defaultValue(a,b);

[pjcozzi]

Thanks @nobelium. Have you sent in a CLA yet? See CONTRIBUTING.md.

@mramato any chance you want to review this? @Andre-Nunes has also done good work on this (#684) so this will need some coordination. In many places, we would benefit from both of their changes, but the merge will be some work.

@nobelium I took a quick glance at the code, and one thing I noticed is we generally do not use defaultValue if constructing the second parameter is expensive, e.g., it allocates something, unless the function is only called rarely (just ask in cases you are not sure). Instead, we use (typeof foo !== 'undefined') ? foo : new Foo().

[mramato]

@nobelium In addition to sending in the CLA, can you please merge in the head of Cesium master? @Andre-Nunes beat you to the punch for some of these and we need to reconcile them before it can be merged.

[nobelium]

@pjcozzi Thanks for the tip. I have changed those lines.
@mramato I have merged the head of Cesium/master , and thanks for the jsHint tip. I used to check for errors using Jasmine.

Regarding CLA, I'm from India, its 23:45 here, I will be able to send it only after 8-10 hrs.

[nobelium]

I have sent my CLA to cla@agi.com , Sorry for the delay, I thought I had to send a physically signed CLA.

[pjcozzi]

@nobelium we have your CLA now. Thanks.

[mramato]

In this case, the original code is actually what we want. this.show is actually a boolean variable. With the check you added, this code executes even when show is false. That's what make this cleanup a little trickier than normal, you need to make sure boolean values stay the same.

[shunter]

This looks good to me. Tests pass. One minor whitespace warning, which I'll fix in master. Thanks for your contribution, @nobelium! Merging.

[shunter]

I'll also fix @mramato's comment about the show, which he's correct about.