This removes .es6 files which are pure duplicates of a
.ts file in the same folder.
Next we need to remove .js files as well, and remove karma preprocessors for dart.
This is a prerequisite for switching to TypeScript. We need to remove the Traceur preprocessor
from Karma, so we have the build specified in a single place (broccoli tree def'n).
Adds a gulp task which builds the .ts files (in the cjs build only).
The new files have extension .ts since they are now valid typescript.
Unfortunately until Typescript can emit System.require, we have to keep the old .es6 version
so traceur works inside the Karma preprocessor. This should be fixed soon.
Alex Eagle
vsavkin