Mention log components in wxLogTrace() documentation.

Using different log components for different logging statements provides a
better (because more general and efficient) way to do the same thing that
wxLogTrace() does, so mention them when describing wxLogTrace().

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62348 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775