PCASpy 0.4 release

[Xiaoqiang Wang <xiaoqiang.wang@psi.ch>]

Hi all,

PCASpy is a Python binding to Portable Channel Access Server. 
It allows creating server applications in pure Python code.

Homepage: https://code.google.com/p/pcaspy/
User Documents: https://code.google.com/p/pcaspy/wiki/UserDocuments

Excerpt from http://pcaspy.googlecode.com/hg/CHANGES
    * Fixed timestamp info. 
        The timestamp is set at each setParam call with new value different to current value.

    * 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 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.


Best
Xiaoqiang