fix stackoverflow in calldataload, codecopy, extcodecopy + some tests
avoid code repetition in vm
minor fix
even less code
Merge remote-tracking branch 'upstream/develop' into newTests
Add exception in vm
state log tests
Merge remote-tracking branch 'upstream/develop' into stateLogTests
Merge pull request #572 from CJentzsch/stateLogTests

State log tests
Remove verbosity.
Merge pull request #571 from ethereum/network

thread-safety, WhisperPeer::sendMessages()
Merge branch 'develop' of github.com:ethereum/cpp-ethereum into develop
return when ciphertext empty