[classlib] Fixed a bug with inheritance

Previously classes inheriting from more than one base class could incorrectly inherit a method. 
	
	classA = {}
	function classA:print()
		print("Hello")
	end

	classB = {}
	function classB:print()
		print("Goodbye")
	end

	classC = inherit(classA)
	inherit(classC, classA)

	instance = new(classC)
	instance:print()

Expected output: "Goodbye" 
Actual output: "Hello"
Output after this fix: "Goodbye"


Also fixed a typo