o.c.scan: Define scan_config.xml to replace beamline.xml

There's a beamline2scan_config.xsl converter, and scan tools will still
read existing beamline.xml files, but issue warnings.
Merge remote-tracking branch 'origin/master' into bug_288
o.c.scan: Use scan_config.xml in all tools

.. but still support beamline.xml & simulation.xml as fallback, with
warning
o.c.scan: Issue only one deprecation warning about
beamline/simulation.xml
o.c.scan: Log complete stack trace for simulation errors
o.c.scan: Simulation config didn't work with plugin:// as path
o.c.scan: Tested OK with deprecated beamline/simulation.xml
Merge pull request #321 from ControlSystemStudio/bug_288

Bug 288