segfault on 64-bit

[briancsparks]

Per the instructions on the libcurl site: you must pass a pointer to a long (not an int) when calling curl_easy_getinfo() with a numeric option (like RESPONSE_CODE).

Line 280 of node-curl.h uses "int" as the CType template parameter, when it should be a "long".

Changing this line and re-compiling fixes the issue for me.