Globally replace _T() with wxT().

Standardize on using a single macro across all wxWidgets sources and solve the name clash with Sun CC standard headers (see #10660).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@61508 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/doxygen/mainpages/const_cpp.h

@@ -288,6 +288,8 @@ for the GUI applications (i.e. those which don't define @c wxUSE_GUI as 0).
         defined when compiling code which uses wxWidgets as a DLL/shared library}
 @itemdef{WXBUILDING,
         defined when building wxWidgets itself, whether as a static or shared library}
+@itemdef{wxNO_T,
+        may be predefined to prevent the library from defining _T() macro}
 @endDefList
 
 */