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
* Started work on multiple msgs, types and x/auth tests pass
* Fix issues in x, examples, and baseapp
* Added baseapp tests for multiple msgs
* Documentation fixes
* Fix baseapp tests with sdk.Int
* Modify test
* Transaction handling is now atomic
* Fix test comment
* Minor doc fixes and code cleanup
* Added baseapp result changes
* Use address in validator update accumulation
* Started work on multiple msgs, types and x/auth tests pass
* Fix issues in x, examples, and baseapp
* Added baseapp tests for multiple msgs
* Documentation fixes
* Fix baseapp tests with sdk.Int
* Modify test
* Transaction handling is now atomic
* Fix test comment
* Minor doc fixes and code cleanup
* Added baseapp result changes
* Use address in validator update accumulation
* Added ante tests for multisigner
* Remove validatorUpdates from tx result
* Better error logs
* Put Memo in StdSignBytes and formatting
* Updated changelog
