Bug 288

This replaces the scan system 'beamline.xml' and 'simulation.xml' with a 'scan_config.xml'.

The old files can still be used, they will generate deprecation warnings.

The new scan_config.xml only lists PVs, alias, slew rates for the scan system.
No IOC, device, … info as in the previous beamline.xml, which is really part of an overall SNS beam line configuration.

A XSL translation is provided to translate beamline.xml into scan_config.xml.