Fix for SystemJS Builder Issue #478
Fix for SystemJS Builder Issue #478

This PR only will check UMD global compile options if globalName or globalDeps are defined as Builder options.
whitneyit/builder,lookfirst/builder,systemjs/builder,whitneyit/builder,alexisvincent/builder,systemjs/builder,jrauschenbusch/builder,jrauschenbusch/builder,lookfirst/builder,alexisvincent/builder,alexisvincent/builder,jrauschenbusch/builder,systemjs/builder