Restrict new windows in replay + improved service worker loading + better error messages (#126)

* embeds:
- support target rewriting with named iframe as per webrecorder/wombat#94
- refactor sw init: detect additional errors, such as CORS issues in nested iframes
- support cross-origin replaybase for embeds
- add 'requirecrossoriginiframe' to restrict embed to only be loaded in subdomain iframes, otherwise showing
- rename noSandbox -> sandbox, not enabled by default

init: set appName on service worker init
docs:
- add example embed to embedding doc
- update docs for noSandbox -> sandbox
- add warning if deprecated 'noSandbox' flag is used, explaining that it is now deprecated
- update embedding and CHANGES.md with latest features
- add tweet-example.wacz
- add embed.html to test embeds

bump to 1.7.0-beta.1

src/loader.js

@@ -3,7 +3,7 @@ import { wrapCss, IS_APP } from "./misc";
 
 import prettyBytes from "pretty-bytes";
 
-import { getSWErrorMsg, parseURLSchemeHostPath } from "./pageutils";
+import { parseURLSchemeHostPath } from "./pageutils";
 
 
 // ===========================================================================
@@ -125,11 +125,11 @@ class Loader extends LitElement
 
     this.percent = this.currentSize = this.totalSize = 0;
 
-    const noSWError = getSWErrorMsg();
+    // const noSWError = getSWErrorMsg();
 
-    if (noSWError) {
+    if (this.loadInfo && this.loadInfo.swError) {
       this.state = "errored";
-      this.error = noSWError;
+      this.error = this.loadInfo.swError;
       this.errorAllowRetry = false;
       return;
     }