Hidden - add parameter Wrap

[skclusive]

Currently <Hidden /> component exposes the media query class via context.Class

ex:

<Hidden SmallUp>
   <Paper Class="@context.Class">content here</Paper/>
</Hidden>

we could add new parameter named Wrap which could wrap the content inside div and style with hidden class.

ex:

<Hidden SmallUp Wrap>
   <Paper>content here</Paper/>
</Hidden>

would wrap the <Paper /> inside a <div />

#21 for details.