Revert "Merge pull request #294 from bitlisp/unified-int-primitives"

This reverts commit 8fed722516b72b59165e5a0bd53fe189245403e3, reversing
changes made to 943b653f35ecc85776b3493a2407e8c888e47703.
Instead of using the installed global idris for tests,
pass the PATH to the current compiled one to test and use this
Build in .travis.yml
Merge pull request #310 from hannesm/use-compiled-idris-instead-of-installed

Instead of using the installed global idris for tests,
Use make test in .travis.yml
Install in .travis.yml
Cache missing cases found by totality checker, for display
Now :missing works correctly (fixes issue #210)
Also, remove a large chunk of unused code in coverage checker.
Fix missing files in idris.cabal
Productivity check fix
Guardedness check didn't actually check it was under a constructor!
Coinductive types do not get smaller! Fix size change graph builder.
Look through call graph for mutual recursion when productivity checking
Otherwise we might miss non-productive calls, particularly important
when using 'with'.
Fixes issue #183