[BUG] Nonce synchronisation

[erdzan12]

The issue #70 was in general fixed by requesting the current nonce from the geth network before submitting a transaction.
However, when two user for example are trying to register themselves near simultaneously the same nonce will be used and thus one transaction will fail as only one transaction can be processed with one nonce, and thus that one nonce is "used up".
The other user will receive an error message.
Therefore, in a distributed environment as in the case of las2peer where one account can be used by different services to submit transactions, which can happen simultaneously the nonce in these situations must be synchronised.

[erdzan12]

A proposed solution is to synchronise the nonce using las2peers distributed storage. This allows for example near simultaneous registrations to be possible as in these case the appropriate nonce is taken.
To allow the modification of the getter methods for the nonce, in the solution a StaticNonceRawTransactionManager wich extends the FastRawTransactionManager is used.