Fix contex-menu in non-editeara

The context-menu `Toggle CoffeeScript Preview` also in tool-panel.
So, add selector `.editor:not(.mini)`, let context-menu only appear in edit-area.

Before:
![before](https://cloud.githubusercontent.com/assets/1926185/3793236/73026192-1b90-11e4-9c1c-b0e499727f12.png)