explicitly cast the after work callback function to "uv_after_work_cb"
explicitly cast the after work callback function to "uv_after_work_cb"

for node >= v0.9.4 compat

unbornchikken/node-ffi,node-ffi/node-ffi,unrealsolver/node-ffi,Icenium/node-ffi,pmuellr/node-ffi,lzpfmh/node-ffi,paulcbetts/node-ffi,Icenium/node-ffi,lzpfmh/node-ffi,unrealsolver/node-ffi,craigcomstocks/node-ffi,skoky/node-ffi,lzpfmh/node-ffi,pmuellr/node-ffi,unbornchikken/node-ffi,paulcbetts/node-ffi,lzpfmh/node-ffi,skoky/node-ffi,node-ffi/node-ffi,unbornchikken/node-ffi,pmuellr/node-ffi,paulcbetts/node-ffi,Icenium/node-ffi,skoky/node-ffi,unrealsolver/node-ffi,pmuellr/node-ffi,craigcomstocks/node-ffi,craigcomstocks/node-ffi,node-ffi/node-ffi,craigcomstocks/node-ffi,Icenium/node-ffi,node-ffi/node-ffi,unbornchikken/node-ffi,paulcbetts/node-ffi,skoky/node-ffi,unrealsolver/node-ffi