Consolidate Fastboot shims

[thec0keman]

Consolidate the import shims of fastboot into the main addon. This should fix #154

It looks as if in fastboot, both the addon/lib and public files were both being evaluated, and the addon one was taking precedence. This resulted in errors like Cannot set property compare of undefined.

I've tested this in both fastboot and the browser, both with timezone and without.

[jasonmit]

This seems reasonable and thank you for taking the time to tackle this. Any chance we can add fastboot tests? Way back when the fastboot story was non existent, unsure if that has changed recently. If it's still complicated then I'm fine with moving forward as-is.

[thec0keman]

Took a stab at some tests

[iamareebjamal]

Interestingly, it was working well for us before in fastboot, but now it throws Cannot set property 'compare' of undefined after this release

[scottmessinger]

We're also running into TypeError: Cannot set property 'compare' of undefined. Not sure the cause yet.

[scottmessinger]

Appears to be an issue upgrading from 3.7.1 to 3.8.0 and running in fastboot.

[jasonmit]

As far as I understand, Fastboot was broken and is now fixed except for the compare proto extension (compare was/is needed so things like Ember.computed.sort work) now missing. If none of that's true, we can probably just revert this this PR and move on.

In short, I really dislike how we've extended the proto of moment to support this Ember features.

Reason being - in the future, the compare method will no longer exist once we migrate off this addon to a ember-auto-import/webpack plugin solution - so we should think about a world where we make it work without this patch.

Perhaps there's a better solution? I don't use Ember or moment anymore in my day job (unfortunately, because I really miss it) - so it's unlikely I'll get around to patching this if the fix is beyond just reverting this commit.

Is this issue something someone else wants to take up? If so, lets open a new issue for tracking since visibility on closed PRs are difficult to find.