Status message should appear only in idris projects

[laughedelic]

When I open whatever project not related to idris, I see the message Idris (Not loaded) in the status bar, which doesn't make any sense in this context:

[archaeron]

You're right, thanks for opening the issue.

[jeremy-w]

A start to fixing this:

  consumeStatusBar: (statusBar) ->
    atom.workspace.onDidChangeActivePaneItem (paneItem) ->
      console.log("active pane item is:", paneItem)
      /* (jws/2015-08-28)TODO: add/remove status based on if it is/not an Idris file */
    @controller.attachStatusIndicator statusBar

It logs whenever I switch tabs. Should be able to spelunk into the provided object to work out if it's an Idris file or not. The best way to go is likely based on the grammar rather than the file extension, since if the grammar is not set to idris, then none of our functions will be available anyway (right?).