- Added documentation and renamed some constants.
- Turned on the acts tracking geometry.

 - using "athena"
 - this avoids any clashing with the reference detector libraries.

 - [x] Add to `BarrelTrackerWithFrame`
 - [ ] Add to `TrapEndcapTracker
 - [ ] Add to other tracking detectors

	modified:   CMakeLists.txt
	modified:   src/BarrelTrackerWithFrame_geo.cpp

- Renamed the vertex and tracker barrel detectors
- Commented out endcap tracker
- Added more detailed to space frame construction.

	renamed:    src/SiVertexBarrel_geo.cpp -> src/BarrelTrackerWithFrame_geo.cpp
	modified:   src/CylinderTrackerBarrel_geo.cpp

	modified:   compact/display.xml

 - Vertex tracker endcaps are simple disk trackers.