ViewPager & Improved WebView

- Applied a ViewPager to the ArticleActivity. It works great but breaks the fading action bar. I may have to work around this.
- Removed deprecated SINGLE_COLUMN WebView layout algorithm.
- Using CSS magic, I overrode max width for images & videos.
- Removed all div tags during parsing to avoid bugs
- Since /attachment/ URLs didn't directly link to images as I thought, they no longer load the image directly.
- Fixed article tags not displaying. (N00b mistake)