Add caching
Add CFG example
Fix build error on GHC 7.4
Try testsuite with alt-ergo, too
Add more CFG examples
Break instantiation loop in monomorphiser
Prove `sum (map length xss) == length (concat xss)`

Also rename join' to concat
Use list-comprehension definition of concat
Merge branch 'master' into fpi

Conflicts:
	src/HipSpec/ATP/Invoke.hs