Fixed bug where halo border would be too tall and catch mouse events.
Now preventing vertical scroll.

Change-Id: I455590afc7da1d005555a268027be448566d580b
Added debug option

Change-Id: I50a4fe94283c7a67b5ec47fbba867263d5042bcb
Improved Equation Editor interface, added help tab.

Change-Id: If06ecc249ace674779bb7867ec1042e8a76b32c0