Suggested variables when undefined, and more

A couple of little fixes, but let's start with the headlining feature.

### sugestions when variable doesn't exist

I tried setting `anti_entrophy = on` in my riak.conf, this was the output
```
➜  riak_ee git:(develop) ✗ ./rel/riak/bin/riak config generate
10:57:23.202 [warning] You've tried to set anti_entrophy, but there is no mapping
10:57:23.202 [warning]   it could be a typo. Did you mean one of these?
10:57:23.218 [warning]     anti_entropy
10:57:23.218 [warning]     anti_entropy.tick
10:57:23.218 [warning]     anti_entropy.expire
```

Oh yeah, suggestions when you make a mistake! This addresses #15 but in a larger than life kind of way

This PR also fixes #19 and #47, which were pretty much the same issue anyway.

Also, @reiddraper noticed a broken test, which I broke in previous merge, but the functionality was correct, I just had to alter the test to compensate.