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/persist.h

@@ -55,8 +55,6 @@ public:
     static wxPersistenceManager& Get();
 
     // trivial but virtual dtor
-    //
-    // FIXME-VC6: this only needs to be public because of VC6 bug
     virtual ~wxPersistenceManager();
 
 
@@ -231,15 +229,8 @@ private:
     wxDECLARE_NO_COPY_CLASS(wxPersistentObject);
 };
 
-// FIXME-VC6: VC6 has troubles with template methods of DLL-exported classes,
-//            apparently it believes they should be defined in the DLL (which
-//            is, of course, impossible as the DLL doesn't know for which types
-//            will they be instantiated) instead of compiling them when
-//            building the main application itself. Because of this problem
-//            (which only arises in debug build!) we can't use the usual
-//            RegisterAndRestore(obj) with it and need to explicitly create the
-//            persistence adapter. To hide this ugliness we define a global
-//            function which does it for us.
+// Helper function calling RegisterAndRestore() on the global persistence
+// manager object.
 template <typename T>
 inline bool wxPersistentRegisterAndRestore(T *obj)
 {