Fixed parse to allow buffers larger than 16 bytes to be used.

[hoylen]

Fixed parse method to allow buffer and offset parameters to be used as intended.

Previously, the code said if (buffer.length != 16) throw ... which means larger buffers cannot be passed in, and the only valid value for offset is zero.

This code change allows for any buffer size as long as the number of bytes between the offset and the end of the buffer is 16 bytes or greater.