Multiple checks without reloading are not working

[ostruk]

I wanted to perform multiple manifest checks without reloading the page. But what happens is that the library toggles the this._updateReady flag to true and never resets it back to false, even after the update is complete. The download function checks for this flag and if it's true, the download is skipped (the promise gets resolved to null). It would be prudent to set the this._updateReady flag to false once the update is complete so that a subsequent call to the download function succeeds.

Similarly, manifest files are being set to blank before download:

this.manifest.files = Manifest.files = {}

And will have to be set to new files after update is complete:

this.manifest.files = Manifest.files = this.newManifest.files;

I'll see if I can do a pull request..