710pre3 tracker-lumi geometry

This request contains new geometry for the tracker to include the lumi detectors PLT and BCM1F. The modifications are available in Geometry/TrackerCommonData/data/test2014 as recommended by the tracker experts.

In addition, the geometries of the lumi detectors, and modifications to make them available, are also included in Geometry/ForwardCommonData.

The modifications only have effect when running the Geometry/CMSCommonData/cmsExtendedGeometryTest2014XML_cfi.py, which is the configuration for the scenario used by the tracker experts for tests.