Replaced 'physical' by 'material' or 'physical-material' when necessary. Maybe review for consistency.
Merge branch 'master' of github.com:sebastien-fauvel/quantum-ethics into issue-3

Conflicts:
	Quantum Field Theory.tex
Used 'quantum state' instead of 'physical state'
Merge pull request #3 from sebastien-fauvel/issue-3

Wording: Say 'material' instead of 'physical'...