Add Ledger & Transaction Specific Flags enums
Use def keyword
Add setXDefaults to known formats
Useful for extrapolating full nodes from metadata
Remove unused file
Add Request.Manager class and some new APIs using it
requestLedger
requestLedgerEntry
requestBookOffers
requestTransaction
Rename BinaryReader to STReader
Add LedgerHashes type to STObject.formatted
Fix bug in json encoding, where 32 bit values were encoded as unsigned, problematic when hi bit set in flags
Update .gitignore
Update AccountID
* Renamed ONE, ZERO accounts to NEUTRAL, XRP_ISSUER
* Added isNativeIssuer() method
* remove equals method
Update Amount
* Add an Amount(Currency, AccountID) constructor for creating zero amounts
* make isPositive a public method
Update Currency class
* Add NEUTRAL and XRP static instances
* Add isIOU method
* Tweak 3 letter currency code validation to allow misshapen codes seen
  in the wild
Add some TYPE_* constants
return buffer directly in toBytes
Add removeUnstable method
Add add(SerializedType st) method
Add isZero() and isNonZero() methods
Add ledgerHashes methods
Update ShaMap package
* Add ShaMapDiff class
* Add AccountStateBuilder
* Rename ShaMapInnerNode -> ShaMapInner
* Rename ShaMapLeafNode -> ShaMapLeaf
* Various helper methods
Make members public