CI: Install mono and enable CSharp on appveyor and bump clang version to 5.0.0 as it is installed on CI.
CI: Install mono and enable CSharp on appveyor and bump clang version to 5.0.0 as it is installed on CI.

rokups/Urho3D,rokups/Urho3D,rokups/Urho3D,rokups/Urho3D,rokups/Urho3D,rokups/Urho3D