Removes production_chain submodule due to its uselessness
Fixes conflicts and merge 'master' of github.com:ekylibre/ekylibre

Conflicts:
	config/locales/arb/action.yml
	config/locales/eng/action.yml
	config/locales/fra/action.yml
	config/locales/fra/models.yml
	config/locales/jpn/action.yml
	config/locales/spa/action.yml
	config/modules.xml
	config/rights.yml
	db/schema.rb
	lib/ekylibre/models.rb