- made the "next scripting laguage" a own, loadable tcl package (currently named nx, name is subject of change) - predefined.tcl is now pretty minimal.
- added section about registering filters and mixin to migration guide - moved and transformed to next tests/mixinoftest.xotcl -> tests/mixinoftest.tcl - moved and transformed to next tests/object-system.xotcl -> tests/object-system.tcl