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/msw/debughlp.h

@@ -19,25 +19,10 @@
 #endif // __WXWINCE__
 #include "wx/msw/private.h"
 
-// All known versions of imagehlp.h define API_VERSION_NUMBER but it's not
-// documented, so deal with the possibility that it's not defined just in case.
-#ifndef API_VERSION_NUMBER
-    #define API_VERSION_NUMBER 0
-#endif
-
-// wxUSE_DBGHELP is a bit special as it is not defined in wx/setup.h and we try
-// to auto-detect whether we should be using debug help API or not ourselves
-// below. However if the auto-detection fails, you can always predefine it as 0
-// to avoid even trying.
+// wxUSE_DBGHELP can be predefined as 0 to avoid the use of dbghelp.dll if this
+// is undesirable for some reason.
 #ifndef wxUSE_DBGHELP
-    // The version of imagehlp.h from VC6 (7) is too old and is missing some
-    // required symbols while the version from VC7 (9) is good enough. As we
-    // don't know anything about version 8, don't use it unless we can test it.
-    #if API_VERSION_NUMBER >= 9
-        #define wxUSE_DBGHELP 1
-    #else
-        #define wxUSE_DBGHELP 0
-    #endif
+    #define wxUSE_DBGHELP 1
 #endif
 
 #if wxUSE_DBGHELP