Merge pull request #86 from vikramrajkumar/master

CLI updates
Fork handling and debug graphs working.
Merge branch 'master' of github.com:BitShares/bitshares_toolkit
fix forking when blocks are added in different order
Revamp undo / pending process

Added new database of enumerated properties that can be set/updated
using the transactional db model.  This should potentially solve the
undo/redo bugs that were sure to show up under the old model.
Implement wallet import/export to JSON (resolves #66)