Update with two new models Muon and SNS combined.
 -- The muon model is a complex muon beamline model done by Goran Skoro
 -- The SNS model is just the proto-shell to start building the SNS
 model. Not actually enough to be called a model really.

 Additionally, removal of removeDeadCell and AlterSurfBase as they are
 not used.
Merge branch 'master' of https://github.com/SAnsell/CombLayer

Conflicts:
	Main/muBeam.cxx
	Main/sns.cxx
	snsBuild/SNSVariables.cxx
	snsBuild/makeSNS.cxx
	snsBuildInc/makeSNS.h