* cmd/tendermint: fix initialization file creation checks
Fixes#989.
The original initialization sequence started to inexplicably
fail
```shell
tendermint unsafe_reset_all
tendermint init
tendermint node --proxy_app=dummy
```
used to fail with
```shell
ERROR: Failed to create node: Couldn't read GenesisDoc file: open
/Users/emmanuelodeke/.tendermint/genesis.json: no such file or directory
```
because the initialization sequence always assumed that the
genesisDoc would only be set if the privValidator was generated.
However, `tendermint unsafe_reset_all` only created the
`priv_validator.json` file which would mean that then running
`tendermint init` would never create the `genesis.json` file
which if following the recommended sequence would then fail
since the `genesis.json` was absent.
* cmd/tendermint: Load PrivValidatorFS if existent, lest generate it
Feedback from @melekes
* change logging messages for init cmd
Refs #989
* protoc: "//nolint: gas" directive after pb generation
Fixes#138
Since we can't add package directives through the protoc
compiler, yet we need to "//nolint: gas" the Go generated
protobuf file, added a script whose purpose is to
go find the "package (\w+)$" declaration after go fmt
was run by protoc.
The competing solutions were more complex and can be
examined by visiting
https://github.com/tendermint/abci/issues/138#issuecomment-352226217
* simplify script
* rewrite script to work on Mac
Lesson articulated by @jaekwon on why we need 80 bits
of entropy at least before we can think of cryptographic
safety. math/rand's seed is a max of 64 bits so can never
be cryptographically secure.
Also added some benchmarks for RandBytes
