Refactor into Modules

[mouyang]

I think it would be more modular if the helpers were in separate modules and brought in as-needed instead of bringing them all in at once.

Here is some background as to why I wanted to pursue this.

I made a branch to track my progress. Any feedback would be appreciated.

[rragan]

Were you thinking of putting one helper per module? How would users consume the ones they wanted? Would we have some default packagings like 1) everything we have now, 2) everything minus the if helper, 3) ?

We could provide a grunt task that would build a custom library of helpers ala what jQuery has under "How to build your own jQuery". This would cater to folks looking to minimize a prebuilt file they would serve from a CDN for their site.

I wrestled with the helper per repo vs multiple helpers in one repo when setting up https://github.com/rragan/dust-motes

In the end, I kept all the helpers in one repo structured as modules I added granularity and version control per helper by putting a package.json and README.md at the root of the js source for each helper. By npm publishing directly from the individual module areas, I can offer versioned npm modules for individual helpers -- https://github.com/rragan/dust-motes/tree/master/src/helpers/control/iterate is an example.

On the server-side, users can selectively consume the npm modules they need and on the client-side with browserify they can build a bundle containing the ones they need.