Improve view only mode

1. Hide all control buttons except run-all button in report mode.
2. Hide paragraph completely (no space for paragraph) when output is hidden.
3. Fix bug that hidden paragraph appears when running note.
4. For fixing 3, I needed to refactor some *BAD* part of the paragraph controller. 
$scope.viewOnly is introduced by #246. Some element's visibility are controlled by this variables.
I think report.css can override visibility of elements without defining and referencing $scope.viewOnly.

What do you think about $scope.viewOnly?