Accounting tests

[jjcnn]

Tests of send and accept, and their effects on the sender's and recipient's balances.

The tests have been designed so that they ought to be easy to incorporate into the blockchain test suite, which is necessary to ensure the correct semantics.

@vaivaswatha has requested that this PR links to Zilliqa/scilla-rtl#46.

[jjcnn]

@vaivaswatha : What's the status on this? Did we solve the C++ side problems?

[vaivaswatha]

@vaivaswatha : What's the status on this? Did we solve the C++ side problems?

@KaustubhShamshery

[jjcnn]

@KaustubhShamshery : Any news on the C++ side of the accounting issue?

[vaivaswatha]

@jjcnn I just merged master to this branch. Can you confirm that it's all sane still?

[jjcnn]

@jjcnn I just merged master to this branch. Can you confirm that it's all sane still?

Everything still looks good. All tests pass, and the code from master doesn't seem to touch anything accounting-related.

[vaivaswatha]

Additional accounting tests

@jjcnn AcceptAndCheckSenderBalance in the support contract doesn't take an expected_balance parameter, but this commit assumes so.

[jjcnn]

Additional accounting tests

@jjcnn AcceptAndCheckSenderBalance in the support contract doesn't take an expected_balance parameter, but this commit assumes so.

@vaivaswatha : Fixed.

I've also fixed the merge conflicts, so the branch should be in order again.