New Filters, an action and drier code.

The new filters now allow you to do this in your Theme functions.php file. This is especially useful for Theme Developers.

Now instead of rolling my own "social icons widget" I can prompt the user to install Tipsy Social Icons, and in my functions.php account for the design that I want (In this case, I want to use Spans with Sprites instead of the <img> tag). 

This is a much better approach than shipping widgets in the theme, which unfortunately many of themes do.

If the user disables my theme one day, he'll still keep the plugin, and fall-back to the default icons. And who knows - if the next theme will have added support for the Icons, the user is going to have a nice and consistent experience. 

I've also added the options to edit/remove/add social networks to the list. While this isn't ideal right now (this should be improved upon, especially with the adding feature), I have the ability to remove some icons in case (for example) I don't have such icon to offer.

To avoid any complications, I've also kept the original icons in the Admin Panel no matter what ( Even if functions.php is customized ). This does mean inconsistency with the front-end design, but I think it doesn't matter that much and it should be just fine.

See previous commits, where I've also dried up the code a lot. 


Let me know your thoughts :)

Examples of the new hooks

`/wp-content/themes/twentytwelve/functions.php`
```php
<?php
// Modify the looks of the Social Icon to hearts content
function modify_social_icon($args) {
	extract($args);
	?>

	I have <?php echo $network ?> and here is the link <?php echo $network_value ?> <br />
	
	<?php
}
add_action('tipsy_social_render_icon', 'modify_social_icon');

```
```php

// Remove Tipsy Options
function remove_tipsy_options($args) {
	return array();
}
add_filter('tipsy_social_options', 'remove_tipsy_options');


```