Add an explicit cast on eio_custom's thread callback, since eio changed that function's signature in node > 0.5.4.
Add an explicit cast on eio_custom's thread callback, since eio changed that function's signature in node > 0.5.4.

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