title: error in running a app in visual studio
body: <p>firstly I installed visual studio 2015 community. at the end of the installation the android sdk, ios and xamarin studio didn't downloaded correctly Message appeared.
  then i was having an offline setup of xamarin studio only so i installed that successfully.
  after that i created a new project by FILE->new project-> visual c# -> android ->blank app on visual studio.
  now when i RUN it, there are many errors like :</p>
  
  <p>Xamarin.Android for Visual Studio requires Android SDK. Please set Android SDK path on Tools->Options->Xamarin->Android Settings menu.</p>
  
  <p>Since i installed only XAMARIN studio not android sdk, so can i install android sdk again externally just like i installed xamarin studio and if YES then How?</p>