Remove MSVC6 support.

Don't support this compiler any more, this allows to get rid of tons of
MSVC6-specific workarounds, in particular we can now use Bind() and natural
template functions calls in the library code.

Also remove MSVC6 project and solution files and don't generate them when
bakefile_gen is ran any more (removing the remaining occurrences of msvc6prj
from the bakefiles results in weird bake-time errors, so it's simpler to just
leave them there).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76532 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/meta/removeref.h

@@ -13,10 +13,6 @@
 // wxRemoveRef<> is similar to C++11 std::remove_reference<> but works with all
 // compilers (but, to compensate for this, doesn't work with rvalue references).
 
-// Except that it doesn't work with VC++ 6 as there doesn't seem to be any way
-// to partially specialize a template for references with it.
-#ifndef __VISUALC6__
-
 template <typename T>
 struct wxRemoveRef
 {
@@ -29,8 +25,9 @@ struct wxRemoveRef<T&>
     typedef T type;
 };
 
+// Define this for compatibility with the previous versions in which
+// wxRemoveRef() wasn't always defined as we supported MSVC6 for which it
+// couldn't be implemented.
 #define wxHAS_REMOVEREF
 
-#endif // !__VISUALC6__
-
 #endif // _WX_META_REMOVEREF_H_