Merges the keybase and Ledger code from go-crypto (which is no more) into the SDK
Adds support for Ledger into gaiacli
Cherry-picks updated error handling from #1158
* Switch ports 4665x to be 2655x
This is done so the default ports aren't in the linux kernel's default ephemeral port range.
* Missed one doc file, change dep so gaiad works
* Update changelog, fix Gopkg.lock