Traditional LoadScript Helper

[SerratedSharp]

Implement helper for traditional loadScript (see SerratedJQ)

function loadScript(relativeUrl) {
return new Promise(function (resolve, reject) {
var script = document.createElement("script");
script.onload = resolve;
script.onerror = reject;
script.src = relativeUrl;
document.getElementsByTagName("head")[0].appendChild(script);
});
}