hgk: enable selected patch text on Windows Port a patch from gitk. Original description: On windows, mouse input follows the keyboard focus, so to allow selecting text from the patch canvas we must not shift focus back to the top level. This change has no negative impact on X, so we don't explicitly test for Win32 on this change. This provides similar selection capability as already available using X-Windows. Signed-off-by: Mark Levedahl <mdl123@verizon.net> Signed-off-by: Paul Mackerras <paulus@samba.org>