added support for unique InitialIterator type in generalized CSR SpMV
added support for unique InitialIterator type in generalized CSR SpMV

baiyunping333/cusp-library,victordion/cusp-library,gshashidhar125/cusp-library,victordion/cusp-library,tectronics/cusp-library,tectronics/cusp-library,baiyunping333/cusp-library,tectronics/cusp-library,vkirangoud/cusp-library,gshashidhar125/cusp-library,gshashidhar125/cusp-library,baiyunping333/cusp-library,victordion/cusp-library,baiyunping333/cusp-library,vkirangoud/cusp-library,gshashidhar125/cusp-library,vkirangoud/cusp-library,victordion/cusp-library,vkirangoud/cusp-library,tectronics/cusp-library