Feature abstract ipc fixes

Changes:
1. Core_Daemon::set() was private, so couldn't be used by daemons
2. Improved memory allocation in SysV
3. Fixed notice on exit, reason was cyclic reference when destroying objects:
PHP Notice: Undefined property: Core_Worker_Via_SysV::$mediator in /opt/PHP-Daemon/Core/Worker/Via/SysV.php on line 95 pid 16905
#0  Core_Worker_Via_SysV->setup_ipc() called at [/opt/PHP-Daemon/Core/Worker/Via/SysV.php:521]
#1  Core_Worker_Via_SysV->release() called at [/opt/PHP-Daemon/Core/Worker/Mediator.php:258]
#2  Core_Worker_Mediator->__destruct() called at [/opt/PHP-Daemon/Core/Worker/Via/SysV.php:53]
#3  Core_Worker_Via_SysV->__destruct()
4. Fix duplicate call for Core_IWorker::setup()