Source: std::string related cleanup

Source/cmCoreTryCompile.cxx

Source/cmExtraCodeBlocksGenerator.cxx

Source/cmExtraCodeBlocksGenerator.h

Source/cmGlobalMSYSMakefileGenerator.cxx

Source/cmGlobalNinjaGenerator.cxx

Source/cmGlobalUnixMakefileGenerator3.cxx

Source/cmGlobalVisualStudio7Generator.cxx

Source/cmGlobalVisualStudio7Generator.h

Source/cmGlobalVisualStudio8Generator.cxx

Source/cmGlobalXCodeGenerator.cxx

Source/cmLocalNinjaGenerator.cxx

Source/cmMakefileExecutableTargetGenerator.cxx

Source/cmMakefileTargetGenerator.cxx

Source/cmNinjaNormalTargetGenerator.cxx

Source/cmNinjaTargetGenerator.cxx

Source/cmOutputRequiredFilesCommand.cxx

Source/cmTryRunCommand.cxx

Source/cmVisualStudio10TargetGenerator.cxx