fix normalizePath edge case issues
fix normalizePath edge case issues

systemjs/builder,lookfirst/builder,systemjs/builder,systemjs/builder,jrauschenbusch/builder,whitneyit/builder,alexisvincent/builder,jrauschenbusch/builder,lookfirst/builder,jrauschenbusch/builder,alexisvincent/builder,whitneyit/builder,alexisvincent/builder