Change in runlevel control for ESS model

[SAnsell]

Master commit : d1a4514

This commit brings in two features that are going to impact RUNNING of the ess model.

(i) FocusPoints

Focus points have been added so that the main moderator can be changed (both lower/upper) or even removed without invalidating beamports or other items that are downstream. There are two focus points (TopFocus/LowFocus) with 4 link points. There have directional axises orthogonal to both the proton direction and the Z axis. The positions of the points can be adjusted with their own variable set but ideally that would remain fixed allowing everyone to modify the moderators.

(ii) GuideBay reduction

I have merged the upper and lower guidebay into one unit, reducing the guidebays from 4 to 2 items.
This accommodates the larger one piece, guideItem insert that exists from 2.0m to 5.5m. Each beamport is now labeled with three joined string:

(i) G1/G2 to indicate right / left

(ii) BLineTop/BLineLow to indicated upper or lower port position [in a no-port config makes no difference]

(iii) Index :: beamline index for angle.

The beamport is now specified e.g. G1BLineTop4 to indicate the top right beamport 4 from the 60deg point.

Previously if you wished to specify a non-default beamport for a beamline you might have used
./ess -r -defaultConfig Single NMX G4BLine4 AA
This is now replaced with
./ess -r -defaultConfig Single NMX G1BLineTop4 AA

Obviously this may cause problems so please report them !!