Have functional styles on line and area <path>s be set in code

line and area <path> elements had CSS classes applied that
carried functional styling with them (no fill on lines, no stroke
on area). It's more robust to apply these required stylings to the
individual elements themselves, rather than as a class.
Merge pull request #1275 from palantir/hotfix-line-area-functional-styling

[HOTFIX] Have functional styles on line and area <path>s be set in code