bugfix: don't use !Kernel.isZero() as we don't want to lose eg leading term when building a Function (eg Tangent[FitPoly[]] )

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24030 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Refactoring towards fast repaint in Touch

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24032 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Refactoring towards fast repaint in Touch

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24033 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e