/*
 * call-seq:
 *    Win32::API#call(arg1, arg2, ...)
 * 
 * Calls the function pointer with the given arguments (if any). Note that,
 * while this method will catch some prototype mismatches (raising a TypeError
 * in the process), it is not fulproof.  It is ultimately your job to make
 * sure the arguments match the +prototype+ specified in the constructor.
 * 
 * For convenience, nil is converted to NULL, true is converted to TRUE (1)
 * and false is converted to FALSE (0).
 */
static VALUE api_call(int argc, VALUE* argv, VALUE self){