* Update selectors for buttons, custom colours.
* Update comments widget to better match theme's comment styles.
* Correct table styles in the editor.
* Correct the button line height in the editor.
* Reorganized some CSS, and removed empty selectors.
* Added styles to prevent side-scroll with full alignments.
* Updated caption font size and colour.
* Added style to make sure video in video block would span full screen.
* Added spacing under the Media & Text block.
* Added styles for definition lists in editor.
* Styled file text link in editor.
