changed all definition of Values to be UpValue defintions

Mathematica 10 has a new  builtin function Values, therefore custom
defintions of Values should be UpValues instead of DownValues.
removed Simplex[2] definition

Mathematica10 introduces the new function Simplex, which conflicts with
this function defintion. As Simplex[2] does not seem to be used anywhere,
there is no really a reason to keep it.