Added default empty constructor to const class cukebins::internal::InvokeArgs
Added default empty constructor to const class cukebins::internal::InvokeArgs

The gcc 4.6.0 on Fedora 15 was issuing the following error: 'const class
cukebins::internal::InvokeArgs' has no user-provided default
constructor. Fixed by added a default (empty) constructor.

konserw/cucumber-cpp,cucumber/cucumber-cpp,meshell/cucumber-cpp,paoloambrosio/cucumber-cpp,AbletonAppDev/cucumber-cpp,meshell/cucumber-cpp,konserw/cucumber-cpp,paoloambrosio/cucumber-cpp,konserw/cucumber-cpp,AbletonAppDev/cucumber-cpp,muggenhor/cucumber-cpp,cucumber/cucumber-cpp,AbletonAppDev/cucumber-cpp,meshell/cucumber-cpp,cucumber/cucumber-cpp,paoloambrosio/cucumber-cpp,muggenhor/cucumber-cpp,muggenhor/cucumber-cpp