Introducing VMFace - common VM interface
Use safe pointers in Executive
Merge branch 'develop' into vm
Revert unnecessary whitespace changes
Merge remote-tracking branch 'origin/vm' into vm
Fix alethzero build
VMFactory - a new way of creating VMs
Merge remote-tracking branch 'upstream/develop' into vm
Style fixes (mostly)
Catch exception by reference
VM::go detemplatized. Cleanups.
Merge remote-tracking branch 'upstream/develop' into vm

Conflicts:
	libethereum/Executive.cpp
	libethereum/Executive.h
	libethereum/State.cpp
Reduce verbosity.
Merge pull request #583 from imapp-pl/vm

VM interface & factory
Fix tests.
Merge branch 'develop' of github.com:ethereum/cpp-ethereum into develop
Minor warning fix.