Fix for #3041 -- was related to x(a) -> x*a autocorrection in CAS; we only checked GeoDummies and not Variables

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@23800 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Speedup: more canvases approach to speedup rejected, as there were times when the two canvases were not in sync

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@23801 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e