account for content wrapped in <p> tags & various fixes

I found this plugin incredibly useful, until the content I was trying to shorten was user-generated from a wysiwyg. Most content gets wrapped in ```<p>``` tags, so it's not just 'floating.' This caused the plugin to break, as it didn't know how to properly handle them, as they were **not** tags *within* the text to be truncated, but rather *wrapping* the entirety of the content.

This pull request does a few things:

1. Update the copyright to 2014
2. use ```<div>``` tags for the ```shortcontent``` and ```allcontent``` wrappers (better semantically, as ```<p>``` tags within ```<span>``` tags is... weird)
3. integrates issue #7 that @henrythewasp addressed
4. removes bottom margin from last ```<p>``` tag in shortcontent (so it actually appears cut off)
5. wraps ellipses text in a ```<span>``` with a class of ```ellip``` so you can style

If anyone has a better approach to account for ```<p>``` tags and other wrapping elements, share em in the comments.