1. '\n's in tooltip messages are handled (replaced by spaces anyhow, tooltip

1. '\n's in tooltip messages are handled (replaced by spaces anyhow, tooltip
    made multiline if comctl32 supports it)
2. added wxTAB_TRAVERSAL to default wxScrolledWindow style
3. improved arrows handling in radiobox (still problems for multirow ones)
4. [Alt]-<mnemonic> works in nested panels as well now because we use
   WS_EX_CONTROLPARENT for all windows with wxTAB_TRAVERSAL style
5. tooltips for radioboxes work again, even if I'm not really satisfied with
   solution :-( but I spent 2 hours trying to make TTM_WINDOWFROMPOINT handler
   work and I don't have more time to waste on this.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@5620 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775