porting StripGeoModelXml (used to be called SCT_GeoModelXml) from 21.9 to...

This is the package StripGeoModelXml (used to be called SCT_GeoModelXML under 21.9, name changed as per Nick Styles' request) being ported to master, thus fulfilling requests in ATLIDTRKCP-206. here follows the list of files being committed:

new file:   InnerDetector/InDetDetDescr/StripGeoModelXml/CMakeLists.txt
new file:   InnerDetector/InDetDetDescr/StripGeoModelXml/StripGeoModelXml/SiHitIdGmx.h
new file:   InnerDetector/InDetDetDescr/StripGeoModelXml/StripGeoModelXml/StripDetectorFactory.h
new file:   InnerDetector/InDetDetDescr/StripGeoModelXml/StripGeoModelXml/StripDetectorTool.h
new file:   InnerDetector/InDetDetDescr/StripGeoModelXml/StripGeoModelXml/StripGmxInterface.h
new file:   InnerDetector/InDetDetDescr/StripGeoModelXml/StripGeoModelXml/StripOptions.h
new file:   InnerDetector/InDetDetDescr/StripGeoModelXml/StripGeoModelXml/WaferTree.h
new file:   InnerDetector/InDetDetDescr/StripGeoModelXml/oldCMakeLists.txt
new file:   InnerDetector/InDetDetDescr/StripGeoModelXml/src/SiHitIdGmx.cxx
new file:   InnerDetector/InDetDetDescr/StripGeoModelXml/src/StripDetectorFactory.cxx
new file:   InnerDetector/InDetDetDescr/StripGeoModelXml/src/StripDetectorTool.cxx
new file:   InnerDetector/InDetDetDescr/StripGeoModelXml/src/StripGmxInterface.cxx
new file:   InnerDetector/InDetDetDescr/StripGeoModelXml/src/WaferTree.cxx
new file:   InnerDetector/InDetDetDescr/StripGeoModelXml/src/components/StripGeoModelXml_entries.cxx

I successfully compiled and built everything under master but I'd certainly appreciate comments and/or corrections

andrea