windows_package Should Search Update Registry Keys In Addition To Uninstall Registry Entries

This PR ensures that when installing a package which happens to be an update to a Microsoft product, windows_package can identify that it is already installed and skip the install.

Windows and Microsoft updates (e.g. Visual Studio 2012 Update 3) do not have uninstall registry key entries; they are tracked separately.

This PR addresses [COOK-3454](http://tickets.opscode.com/browse/COOK-3454).