Enhanced Mobility Publish and Subscribe API backend and documentation for Symbian

Currently Mobility P&S API documentation isn't helpful for developer identifying what are the values developer can access with it. There is also no way to currently access Feature Manager information of Symbian OS.

This task will:

• Add numerical ID possibility to the P&S paths meaning user of the API would be able to use directly symbian identifiers without hassle of QCRML files
• Add feature manager access (in addition to Symbian P&S and central repository)
• Document how to find the key IDs to Mobility P&S Symbian section, or link to the documentation, or optionally autogenerate Qdoc from available Symbian data
• Optionally, enable QCRML autogeneration from Symbian cenrep keys to Symbian image creation