Added behavioral diversity ability
Added input and output stacks, as well as some relevant instructions
Updated odd problem for input stack
Changed "demos" problem files to use new input stack.
Updated regression problems for input stack
Merge branch 'io-stacks' into behavioral-diversity

Conflicts:
	src/clojush/problems/integer_regression/factorial.clj
Added registered-for-stacks, which returns all instructions for a list of stacks
Added 'use of clojure.set
Version bump.