cssRule interpolation and deduping

This release updates to the latest version of free-style. This version allows for using $nest in normal cssRule() and includes css rules in css de-duplication.

Move output to `/lib`

• Instead of import * as csx from 'typestyle/csx' you now need to do import * as csx from 'typestyle/lib/csx' this is because previously we made you recompile csx and now we ship the compiled .js files

Key reasons for doing this change:

• work with ts-loader
• preserves outDir option for nodejs users
• The definition .d.ts files are picked up by the ts compiler instead of .ts and so you can use the strictest TypeScript features without having to also recompile our code.