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

Was casting left to Extended, (or Double) when Left was IE: a single
whenever Right was extended or 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 within assigning it, it will
still leak the resulting array. But who does that anyway??
Merge pull request #2 from WarPie/master

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