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

tests/strings/vararg.cpp

@@ -124,12 +124,10 @@ void VarArgTestCase::CharPrintf()
 
     // test char used as integer:
     #ifdef _MSC_VER
-        #pragma warning(disable:4305) // truncation of constant value in VC6
         #pragma warning(disable:4309) // truncation of constant value
     #endif
     c = 240;
     #ifdef _MSC_VER
-        #pragma warning(default:4305) // truncation of constant value in VC6
         #pragma warning(default:4309)
     #endif
     s.Printf("value is %i (int)", c);
@@ -241,13 +239,7 @@ void VarArgTestCase::ArgsValidation()
     // but these are not:
     WX_ASSERT_FAILS_WITH_ASSERT( wxString::Format("%i", "foo") );
     WX_ASSERT_FAILS_WITH_ASSERT( wxString::Format("%s", (void*)this) );
-
-    // for some reason assert is not generated with VC6, don't know what's
-    // going there so disable it for now to make the test suite pass when using
-    // this compiler until someone has time to debug this (FIXME-VC6)
-#ifndef __VISUALC6__
     WX_ASSERT_FAILS_WITH_ASSERT( wxString::Format("%d", ptr) );
-#endif
 
     // we don't check wxNO_PRINTF_PERCENT_N here as these expressions should
     // result in an assert in our code before the CRT functions are even called