Add Visual Studio 2013 support

Now we can use this cookbook to install Visual Studio 2013 by simply
overriding the attributes in a Chef "roles" file or your own local
attributes files.

Here is an example of what I used in a Chef roles file

source = File.join("http://my/server/visual-studio")
year = "2013"

default_attributes ({
"visualstudio" => {
"edition" => "premium",
"premium" => {"filename" =>
'en_visual_studio_premium_2013_with_update_2_x86_dvd_4238022.iso'},
"year" => "2013",
"version" => 'vs' + year,
}
})

override_attributes ({
"visualstudio" => {
"source" => source,
"install_dir" => (ENV['ProgramFiles(x86)'] || 'C:\Program Files (x86)')
+ '\Microsoft Visual Studio 12.0',
"premium" => {"checksum" =>
'5733F60889EDA9DDAB6A84A6C8EBB628DD85C43D17BFFCB992ABDDBA0E268746',
"package_name" => "Microsoft Visual Studio Premium 2013"},
"admin_deployment_xml_file_src" => File.join(source,
'/AdminDeployment-xml/2013/AdminDeployment-2013-premium-4238022-with-update-2.xml'),
"admin_deployment_xml_file_checksum" =>
"91FF0900159304E3EC583B816123C70232F4D68E7118B49EC507D17435556696",
}
})

run_list(
"recipe[visualstudio]"

)