Unify order parsing with a parse() method

[Desrever Nu]

I observed that in the excoin wrappers there is some code duplication : both in getOrderDetails and getActiveOrdersImpl , while parsing the orders.

I wish to see a parse() method that returns a Order object instead

[Sam Griffiths]

single method now exists that removes the duplicate code

[Desrever Nu]

sam merged duplicate code