Add writeMaxFloat and writeMaxInt
Fixed code to match with Java sources.

- Removed extra lines in ereader for OpenOrder
- Make Contract.UnderComp a pointer as in the Java version
- struct Order now has a constructor called NewOrder.
- ScannerSubscription missing Instrument
Implement all remaining TODOs in eclientsocket.go
Add support to subscribe/unsubscribe to all Reply messages
Merge pull request #3 from dsouzae/master

Implement all remaining TODOs in eclientsocket.go