Address: remove Address.Error

By removing Address.Error, we remove a code smell.
This part of the code base was also not under any form of test.
Test data and tests have therefore been added verifying its behaviour in
both Wallet and Address tests.
wallet: fix address description typo
ensures that pubKey length is greater than m
ensure that pubKey length is greater than m

use Array.isArray over instanceof

error message
Merge pull request #198 from thallium205/master

ensure pubkeys length greater than m
tests: fix #198 indentation
integration: stop async tests causing wrong balance
integration: use Script.getHash