For efficiency reasons, text controls no longer set the string for each text updated...

For efficiency reasons, text controls no longer set the string for each text updated event, but rather query for the string value only when GetString is called from an event handler

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@31459 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775