Fix FileStream test case.
Revert "width is a integer value, this is enforced by swig-2.0"

Add test cases for non Integer assignment to FXuchar, FXshort and FXint.

It's typically possible to assign Float values to methods expecting
Integers and we also shouldn't break compatibility.

This reverts commit 3360c669df027835ca8a06e69574478a4faa8d51.