Removed MathPiper strings from ExpressionNode

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25872 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
[giac] make sure {1,2,3}^2 works

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25873 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
rotations : functions, curves

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25874 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
[giac] set difference working

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25875 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
4.9.143.0

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25876 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e