Clean up class initialization methods using methods instead of hash setters

[ronaldtse]

e.g.

unitsml-ruby/lib/unitsml/quantity.rb

Lines 30 to 40 in 4939d85

	def initialize(id, hash)
	begin
	@id = id
	@dimension = hash["dimension_url"].sub(/^#/, "")
	@type = hash["quantity_type"]
	hash["quantity_name"] and @names = hash["quantity_name"]
	@units = serialize_units(hash["unit_reference"])
	# rescue
	# raise StandardError.new "Parse fail on Quantity #{id}: #{hash}"
	end
	end