Updating readme with new min Umbraco versions and info about VPP

Author: Jeavon

README.md

@@ -4,7 +4,7 @@
 
 [![Build status](https://ci.appveyor.com/api/projects/status/mn5hxj5ijurwih7q?svg=true)](https://ci.appveyor.com/project/JamesSouth/umbracofilesystemproviders-azure)
 
-An [Azure Blob Storage](http://azure.microsoft.com/en-gb/develop/net/) IFileSystem provider for [Umbraco](https://umbraco.com) 6.25+. 
+An [Azure Blob Storage](http://azure.microsoft.com/en-gb/develop/net/) IFileSystem provider for [Umbraco](https://umbraco.com) 7.1.9+. 
 Used to offload static files in the media section to the cloud.
 
 Designed to supersede [UmbracoAzureBlobStorage](https://github.com/idseefeld/UmbracoAzureBlobStorage) by [Dirk Seefeld](https://twitter.com/dseefeld65) (With his blessing) this package allows the storage and retrieval of media items using Azure Blob Storage while retaining the relative paths to the files expected in the back office.
@@ -97,7 +97,7 @@ Additionally the provider can be further configured with the following applicati
 ## Virtual Path Provider
 By default the plugin will serve files transparently from your domain or serve media directly from Azure. This is made possible by using a custom [Virtual Path Provider](https://msdn.microsoft.com/en-us/library/system.web.hosting.virtualpathprovider%28v=vs.110%29.aspx) included and automatically initialised upon application startup. This can be disable by adding the configuration setting noted above.
 
-**Note:** Virtual Path Providers may affect performance/caching depending on your setup as the process differs from IIS's [unmanaged handler](http://www.paraesthesia.com/archive/2011/05/02/when-staticfilehandler-is-not-staticfilehandler.aspx/). Virtual files sent via the provider though are correctly cached in the browser so this shouldn't be an issue.
+**Note:** Virtual Path Providers may affect performance/caching depending on your setup as the process differs from IIS's [unmanaged handler](http://www.paraesthesia.com/archive/2011/05/02/when-staticfilehandler-is-not-staticfilehandler.aspx/). Virtual files sent via the provider though are correctly cached in the browser so this shouldn't be an issue. VVP proivders also **don't work** with **Precompiled sites** or when used in a **virtual directory/application**.
 
 The following configuration is required in your `web.config` to enable static file mapping in IIS Express.