Better coloring for template strings

[mihhail-lapushkin]

With the current coloring the string part blends with the code. Would be great to color string parts in the same color as strings. This also goes for the color of backticks.

[derekcicerone-zz]

Yeah, I've flagged this concern with the TypeScript devs (microsoft/TypeScript#1477) but I'm not sure what more we can do. It sounds like they have better support coming in 1.5 or possibly 1.6.