The latest rxjs release works with closure compiler out of the box.
We no longer need to compile our own.
Also put closure options into a file rather than using a shell script.
TypeScript compiler will now build to ES2015 code and modules. Babili is used to minify ES2015
code, providing an initial optimization that we couldn't previously get just from Uglify. Uses
Babel to convert ES2015 to UMD/ES5 code, and Uglify to minimize the output.
