0.4.1 (23-04-2013)
    * Fixed PV initial status. By startup, it is UDF/INVALID.
    * Driver.setParam makes a copy of list/numpy.ndarray objects. This solves the racing condition, in which the value could be in the middle of updating while CA client reads the value. 

0.4 (14-01-2013)
    * Change from GPL to New BSD License for broader audience.
    * Added __version__ info
    * Added access security control
        access security control file can be loaded using SimpleServer.initAccessSecurityFile(filename, **subst). 
        The loaded rules can then be assigned to PV's "asg" field.
        example/access_control.py provides an example and better exaplained in UserDocuments
        https://code.google.com/p/pcaspy/wiki/UserDocuments#Example_5:_Access_Security_Control

    * Added new type char. 
        It is used to represent a long string (>40 chars). And it behaves just like string parameters in driver.
        example/pysh.py provides a concrete example, in PV "COMMAND" and "OUTPUT".

    * Added timestamp info. 
        The timestamp is set at each setParam call with new value different to current value.
    
    * Added alarm/severity info.
        For "enum" type PV, the severity is configued by its "state" field. It is a list of severity states, which can be NO_ALARM, MINOR_ALARM, MAJOR_ALARM, INVALID_ALARM. If current state's severity is other than NO_ALARM, alarm is STATE_ALARM.
        For "int" or "float" type PV, the alarm state is configured by its "low","high","lolo","hihi" fields, in analogue to EPICS database. 
        example/alarm_severity provides an example.

0.3 (21-09-2011)
    * Fixed gdd vector memory leak introduced in 0.2
    * Added casPV's writeNotify method for EPICS base 3.14.11+
    * Release GIL for each C function call
    * Added tools.ServerThread running server process in separate thread
    * Added preliminary Qt GUI integration example using tools.ServerThread

0.2 (16-08-2011)
    * Added Python 3 support
    * Added numpy data types support
    * Fixed the driver registration issue.
    * Rework gdd put/get methods
    * Added gdd unittest cases
    * Remove Makefile in favor of setup.py

0.1 (19-07-2011)
    * Initial release.
