AGW on Phoenix: add `__lt__` and `__gt__` methods to the `FixedPoint` class in `FloatSpin`, as Python 3 is funnier than I thought.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/Phoenix/trunk@73586 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775