Support number-style parameters for all inputs.

As mentioned in #44 it could be nice to support `0x0000`-style input for all 16/64 bit parameters for the frame builder besides `[0x00, 0x00]` and `"0000"`-style. For 16 bit, we can check for type of the parameter value (is it `'number'`?) and then use `reader.appendUInt16BE()`. For 64 bit params, the buffer-reader would need to be extended to support `reader.appendUInt64BE()`
