Enhancements to my previous commit about formula background colors

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@23985 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Removed debugging

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@23986 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e