fix: Suppress closure compiler warnings about unknown 'process' variable.
fix: Suppress closure compiler warnings about unknown 'process' variable.

Needed to compile angular2 apps with closure compiler.

Closes #295

mlaval/zone.js,mhevery/zone.js,mlaval/zone.js,mlaval/zone.js,richardmurri/zone.js,juliemr/zone.js,mhevery/zone.js,mhevery/zone.js,angular/zone.js,richardmurri/zone.js,mlaval/zone.js,juliemr/zone.js,angular/zone.js,richardmurri/zone.js,juliemr/zone.js,angular/zone.js,angular/zone.js,richardmurri/zone.js,angular/zone.js,juliemr/zone.js,mhevery/zone.js