Templating and un-polluting global namespace

![image](https://cloud.githubusercontent.com/assets/2180424/3059653/5068abd6-e1ee-11e3-9173-5ec45cc92ab6.png)

### Folded global functions and variables into object
Globals current, totalEntries, etc are now part of the photoGrid object and are initialized with the call to initGlobals(). Some jQuery selectors were also cached to improve performance.

### Reduce embed code
Used Handlebars.js for HTML templating, reducing the amount of HTML needed to copy + paste. With Handlebars.js and its templates, the number of dependencies have increased. Templates are precompiled for performance.

### Change method of passing key
```javascript

photoGrid.init({
	googleKey: "0AurS2EUbrPERdE9Nc1dMSGdfenFCN0FCTk9jZF9TVWc"
});
```

### Updated README
Updated to include Handlebars. and also corrected /img to /imgs in the subsection "What's in here?" __DID NOT update the subsection "How to use this."__