Fix cancelling choice of custom colour in wxPropertyGrid.

When using wxPGEditor_Choice colour property, cancelling the choice of the
custom colour reset the previously selected custom colour.

Fix this by correcting the test for the custom colour which didn't work
before.

Closes #15542.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76627 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add support for "hint" property in wxTextCtrl XRC handler.

It is convenient to allow specifying the hints directly in the resources.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76628 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775