Allow showing / hiding input bar from menu

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34595 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Putting back code that was removed by mistake

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34596 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Input bar fix

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34597 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e