Changed error vectors from lists to vectors for optimization of lexicase.
Merge branch 'master' into lexicase-vector-speedup
Merge branch 'master' into lexicase-vector-speedup
Merge branch 'master' into lexicase-vector-speedup
Merge branch 'master' into lexicase-vector-speedup
Merge branch 'master' into lexicase-vector-speedup
Merge branch 'master' into lexicase-vector-speedup

Conflicts:
	src/clojush/evaluate.clj
Merge branch 'master' into lexicase-vector-speedup
Fixed levenshtein distance for empty sequences. Also, removed extraneous
line from agent error handlers.
Merge remote branch 'thelmuth/fix-levenshtein'
thelmuth/lexicase-vector-speedup + thelmuth/fix-levenshtein