Refactoring of remainder of History text into skeleton/slots

For the history text, outstanding properties was converted into slots. Numerous skeleton related styling overrides were condensed, refactored out, or in one case, the property added to precalculus to alleviate an issue. Code was refactored down to utilize most prevalent/default slot for styling.

For the new CSS files generated, this was because of a simple addition of a property to the p tag in the section abstract section in precalculus skeleton.  By placing the left align for text here, I can take it out of history entirely.  For all paragraphs/bulleted list items in learning objectives, all items should be left justified anyway.  This is just  clean way to do it without writing additional code and cleaned up history skeleton considerably, but it will generate a new CSS for psychology, precalculus and economics.