TLW default item changes have changed Enter key processing: it was now handled as...

TLW default item changes have changed Enter key processing: it was now handled as TAB even for controls such as wxTree/ListCtrl which need it themselves; fix this by checking for VK_RETURN in these classes MSWShouldPreProcessMessage() implementation; also removed specific test for wxTextCtrl in wxWindowMSW::MSWProcessMessage() and simplified its code

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@40405 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775