JacORB subsystem: allow configuration of initializers as attributes.

Initializers are currently configured as a comma-separated list of names in the <ininitializers> element:

<initializers>SAS,CSIv2,Codebase</initializers>

A better approach would be to allow the declaration of the interceptors as attributes of the initializers element:

<initializers sas="on" csiv2="on" codebase="on" tx="off"/>

This would make this element consistent with the other elements used to configure the jacorb subsystem.