1. wxDialogs are now destroyed when they go out of scope

1. wxDialogs are now destroyed when they go out of scope
2. [GS]etDefaultItem() are now in wxPanel, not wxWindow
3. better checking for g_isPainting - hopefully no more false asserts
4. wxListCtrl not recreated any more when view changes, this corrects
   the bug with selection not working after view mode change
5. wxListCtrl now generates wxEVT_ITEM_ACTIVATED event
6. you can now press/toggle a button with a space
7. couple of other minor fixes

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@2820 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775