Revert e3d9254, be25785 and 0b73d20 commits ("tabsonbottom" attribute).

This reverts commits:

e3d9254d598296a08452861843795df59e48256d,
be25785cd768f9b7ff3f3edce7b04842d41c0cc3,
0b73d2070518f4038b371da2fd6dae8e0125aeef.
Fix toolbar-drag and customizing mode