Replace timestmap 0 value with '0000-00-00 00:00:00'
@B331:R Fixed a bug caused by taking a reference of a constant argument.  A constant may or may not be stored in memory.  When it's not stored in memory (i.e. the value is hardcoded in the code), it has no reference to the value.  However, the existing code was taking a reference of a constant.  This has been working fine so far, but not any more on Ubuntu 14.04.  Changed the code to pass a variable to the constractor of Protocol_chunk which does the error-prone referencing.
@B331:R It turned out that non-constant values also has the same issue.  Turned them to local variables which is known to be safe.