Fixed bug in "Asgn to", related to float types.

**Fix "Assign to"**
Whenever Left was Single, and Right was > Single, I casted left-result to what ever type Right was. Which is not a very good idea!  ... Same goes for Double..

**Fix for plugin leak.**
As long as the `result` is assigned to a `script variable` the arrays
will not leak anymore.

If the function is only called in a loop without assigning it to a variable, it will
still leak the resulting array. But who does that anyway (Olly does not count)??