It was not acceptable to call the class method from the static initializer

It was not acceptable to call the class method from the static initializer
because it caused the load and initialize methods to be called.  Some of the
load and initialize methods used autorelease which would lead to warnings
about memory leaks (true, though very benign).
This version delays all Objective-C calls until InitializePosers().

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@21585 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775