cmGlobalVisualStudioGenerator: Drop VS7 enumeration value

We no longer support the VS 7.0 (.NET 2002) IDE, so drop the enumeration
value corresponding to its version.

Source/cmGlobalVisualStudio7Generator.cxx

@@ -54,7 +54,6 @@ cmGlobalVisualStudio7Generator::cmGlobalVisualStudio7Generator(
     this->DefaultPlatformName = platformName;
   }
   this->ExtraFlagTable = cmVS7ExtraFlagTable;
-  this->Version = VS7;
 }
 
 cmGlobalVisualStudio7Generator::~cmGlobalVisualStudio7Generator()

Source/cmGlobalVisualStudioGenerator.h

@@ -32,7 +32,6 @@ public:
   /** Known versions of Visual Studio.  */
   enum VSVersion
   {
-    VS7 = 70,
     VS71 = 71,
     VS8 = 80,
     VS9 = 90,

Source/cmQtAutoGeneratorInitializer.cxx

@@ -681,11 +681,11 @@ void cmQtAutoGeneratorInitializer::InitializeAutogenTarget(
   if (gg->GetName().find("Visual Studio") != std::string::npos) {
     cmGlobalVisualStudioGenerator* vsgg =
       static_cast<cmGlobalVisualStudioGenerator*>(gg);
-    // Under VS >= 7 use a PRE_BUILD event instead of a separate target to
+    // Under VS use a PRE_BUILD event instead of a separate target to
     // reduce the number of targets loaded into the IDE.
     // This also works around a VS 11 bug that may skip updating the target:
     //  https://connect.microsoft.com/VisualStudio/feedback/details/769495
-    usePRE_BUILD = vsgg->GetVersion() >= cmGlobalVisualStudioGenerator::VS7;
+    usePRE_BUILD = true;
   }
 #endif
 

Source/cmVisualStudioGeneratorOptions.cxx

@@ -101,7 +101,6 @@ void cmVisualStudioGeneratorOptions::FixExceptionHandlingDefault()
   // the flag to disable exception handling.  When the user does
   // remove the flag we need to override the IDE default of on.
   switch (this->Version) {
-    case cmGlobalVisualStudioGenerator::VS7:
     case cmGlobalVisualStudioGenerator::VS71:
       this->FlagMap["ExceptionHandling"] = "FALSE";
       break;