Hotfix for tagRangeFinder added

Added hotfix of rewritten tagRangeFinder function that Marijn wrote
yesterday. Can be removed when CodeMirror 3.2 is released and we upgrade
to that.
Now considering depth on highlight nest

Made this chunk of code active by removing 1==2 condition.
Now also defining 3 events in a variable and applying to text section
and arrow start ends. Also needed cursor: pointer.