Fix for: Basic support for :set statusline #1350

Hi Jared,

please review my fix. 

I add 2 new settings: 
* set laststatus=[Number] - 0 means off and some other value means on.
* set statusline=[Message] - Message will be, as it is, showed.  

I had name conflict with CommandMargin.StatusLine. I renamed it to StatusInCommandLine. Is that OK?