Updates to allow verify_ledger_json.js to calculate account_state hash
Less slicing and dicing of tag_segment/indexes
Reinstate disabled test (Thanks to encoded reminder)
Remove all traces of (now) unused tag_segment
Fix *U*Int64 parsing, add hardcore mode to ledger verifier.
Switch to Istanbul for code coverage. Add coverage to CI via coveralls.
Re-enable Travis email notifications.
Merge pull request #77 from justmoon/feature/coveralls

Switch to Istanbul for code coverage
Add binary <--> json encoding integration tests
* Add full json ledger dumps of ledgers 38129 and 40000 to test/fixtures
* Use `Ledger` to calculate account and transaction hashes and verify
  against dumps
Tweak to parse_options
Update SerializedObject.from_json tests
Fix merge conflicts
Merge branch 'develop' of https://github.com/ripple/ripple-lib into develop
[CHORE] include superagent, vault-test
[FEATURE] ripple.txt client
[FEATURE] authinfo module
[CHORE] update comments
[FEATURE] vault, blob, and crypt module
[DOC] vault client comments
[FEATURE] register blob