Skip VS <= 7.1 dependency analysis for VS >= 8

Commit 1a0c166 (Store direct dependencies in solutions for VS >= 8,
2010-08-20) disabled use of VS-specific global dependency analysis.
Avoid perfoming the analysis at all when it is not needed.  This also
prevents creation of bogus and unused '_UTILITY' targets since they are
not needed for dependencies.

Source/cmGlobalVisualStudio8Generator.cxx

@@ -288,6 +288,14 @@ cmGlobalVisualStudio8Generator
     }
 }
 
+//----------------------------------------------------------------------------
+bool cmGlobalVisualStudio8Generator::ComputeTargetDepends()
+{
+  // Skip over the cmGlobalVisualStudioGenerator implementation!
+  // We do not need the support that VS <= 7.1 needs.
+  return this->cmGlobalGenerator::ComputeTargetDepends();
+}
+
 //----------------------------------------------------------------------------
 void cmGlobalVisualStudio8Generator::WriteProjectDepends(
   std::ostream& fout, const char*, const char*, cmTarget& t)

Source/cmGlobalVisualStudio8Generator.h

@@ -78,6 +78,7 @@ protected:
   virtual void WriteProjectConfigurations(std::ostream& fout,
                                           const char* name,
                                           bool partOfDefaultBuild);
+  virtual bool ComputeTargetDepends();
   virtual void WriteProjectDepends(std::ostream& fout, const char* name,
                                    const char* path, cmTarget &t);