Obsolete function. Use curl_easy_escape(3) instead!
This function will convert the given input string to an URL encoded string and
return that as a new allocated string. All input characters that are not a-z,
A-Z or 0-9 will be converted to their "URL escaped" version (%NN where NN is a
two-digit hexadecimal number).
If the length argument is set to 0, curl_escape() will use strlen() on the
input url string to find out the size.
You must curl_free() the returned string when youre done with it.