* Update drop cap positioning.
* Add italics to verse block, to differentiate it.
* Update selectors for button blocks, for better custom colour fallbacks.
* Update colour selectors, to account for :visited state.
* Update latest comments block to look more like theme's comments.
* Correct table header background colour; remove unneeded borders from table in editor.
* Add spacing under audio, media & text blocks
* Removed empty selectors
* Add border below captions to match non-block content
* Make sure all centred widgets are styled the same
* Add styles for definition lists in editor
* Remove border, border radius from code block in editor
* Add styles to link in file block in editor.
