Robust handling for truncated UCS-2 PDUs

• Added robust handling for truncated UCS-2 PDUs.
• The library now logs a warning and returns an ellipsis at the end of the decoded string to indicate that the data was incomplete.
• The decoded result now contains a warning field when a truncation occurs.

2.1.0

Added outgoing SMS decoding capability

2.0.2

Improved build tools