Keep z coeff when equals 0 for dependent plane

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34014 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Fix 3D visibility check

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34015 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Avoid scrollbars in office app if possible

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34016 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e