switching default CAS back to Reduce

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25101 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Removed unnecessary override

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25102 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Make recomputing coords in Touch consistent (same offset for touch start and touch move)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25103 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Pulled up lastSelectedGeo

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25104 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e