[FIX] Cannot use demmurage currencies in path_find

Use hex format instead of json for currencies.
Merge pull request #127 from orzFly/patch-1

[FIX] Cannot use demmurage currencies in path_find
Update unfunded order tracking
Fix native/non-native currency discrepancies
Uncomment tests
Merge pull request #146 from ripple/unfunded-orders

Update unfunded order tracking - fix native/non-native currency discrepancies
Fix setting funded amount
Merge pull request #148 from ripple/unfunded-orders

Fix setting funded amount
Merge pull request #147 from ripple/develop

Update unfunded order tracking - fix native/non-native currency discrepancies