This commit adds several more attributes from the NSParagraphStyle properties, including the firstLineHeadIndent, headIndent, tailIndent, maximumLineHeight, minimumLineHeight, paragraphSpacing, and paragraphSpacingBefore properties. Unit tests have also been added to test these new properties.

Changing the paragraphSpacing to paragraphSpacingAfter to be clearer as to which paragraph spacing this affects.

It now matches the renamed paragraphSpacingAfter property.

This test case attempts to cover the behavior when you have both the headIndent and indentSpacer set.