Investigate Perkeep

Install instructions
-----------------------

```
mkdir /tmp/perkeep
cd /tmp/perkeep
git clone https://github.com/perkeep/perkeep.git .
# take just any turbobob.json from my Go projects BUT remember to change the project name
bob dev --ignore-nag
go run make.go
mkdir rel
cp /go/bin/{pk,perkeepd,pk-get,pk-put,pk-mount,scanningcabinet} ./rel/
```