Downloads and installs the OCRPro add-on (it's typically a zip file) on the local system.
.Addon.OCRPro.Download(remoteFile, optionalAsyncSuccessFunc, optionalAsyncFailureFunc);
remoteFile: specifies the url path of the add-on. E.g. "http://www.dynamsoft.com/DWT/Resources/OCRPro.zip".
optionalAsyncSuccessFunc: callback function triggered when the file is downloaded successfully.
optionalAsyncFailureFunc: callback function triggered when the file failed to be downloaded.
The version number of the addon is defined in the addon JS file. As long as the defined version number is not the same as the local addon dll, the download method will auto get the dll from server deployed to local.