Shaders : set fading texture

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30700 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
#3914: fixed the Sequence Sequence Curve part

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30701 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Removed debugging

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30702 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e