[giac] fix for Sum[Sum[x+2y, x, 1, 3], y, 2, 4] (mistake in r37600)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@37681 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Input bar help improvements

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@37682 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
drag and drop for touch (preview element of dragged row)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@37683 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e