Creates an IccBuf object, allocating its own data area with the given length and with all the bytes within it set to NULL.
Creates an IccBuf object that cannot be extended, adopting the given data area as its own.
See warning about Internal/External ownership of buffers.
Creates an IccBuf object, allocating its own data area with the same length as the text string, and copies the string into its data area.
The copy constructor--creates a new IccBuf object that is a copy of the given object. The created IccBuf object always has an internal data area.