Added fftconvolve() C API
Added fftconvolve() C API

bkloppenborg/arrayfire,munnybearz/arrayfire,hshindo/arrayfire,unbornchikken/arrayfire,jramapuram/arrayfire,umar456/arrayfire,jramapuram/arrayfire,mrgloom/arrayfire,linan7788626/arrayfire,HolyGeneralK/arrayfire,jramapuram/arrayfire,pombredanne/arrayfire,unbornchikken/arrayfire,merlin-ext/arrayfire,bkloppenborg/arrayfire,marbre/arrayfire,shehzan10/arrayfire,merlin-ext/arrayfire,asifmadnan/arrayfire,pombredanne/arrayfire,ghisvail/arrayfire,shehzan10/arrayfire,hshindo/arrayfire,9prady9/arrayfire,unbornchikken/arrayfire,9prady9/arrayfire,arrayfire/arrayfire,marbre/arrayfire,pombredanne/arrayfire,Keno/arrayfire,unbornchikken/arrayfire,victorv/arrayfire,pentschev/arrayfire,hshindo/arrayfire,linan7788626/arrayfire,victorv/arrayfire,arrayfire/arrayfire,mrgloom/arrayfire,asifmadnan/arrayfire,umar456/arrayfire,bkloppenborg/arrayfire,victorv/arrayfire,pentschev/arrayfire,Keno/arrayfire,pentschev/arrayfire,bkloppenborg/arrayfire,victorv/arrayfire,9prady9/arrayfire,linan7788626/arrayfire,shehzan10/arrayfire,merlin-ext/arrayfire,munnybearz/arrayfire,mrgloom/arrayfire,ghisvail/arrayfire,arrayfire/arrayfire,asifmadnan/arrayfire,HolyGeneralK/arrayfire,HolyGeneralK/arrayfire,jramapuram/arrayfire,shehzan10/arrayfire,linan7788626/arrayfire,marbre/arrayfire,munnybearz/arrayfire,pombredanne/arrayfire,arrayfire/arrayfire,Keno/arrayfire,merlin-ext/arrayfire,9prady9/arrayfire,HolyGeneralK/arrayfire,marbre/arrayfire,mrgloom/arrayfire,Keno/arrayfire,hshindo/arrayfire,umar456/arrayfire,umar456/arrayfire,pentschev/arrayfire,asifmadnan/arrayfire,ghisvail/arrayfire,ghisvail/arrayfire