Reset values (sometimes set by previous use of intersection curve)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@23444 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
better error handling and bugfixes in CmdIntersect

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@23445 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Cube[point,point], etc.

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@23448 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Remove unused methods

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@23449 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e