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
String types.
Tests for empty and too long strings.
Helper functions to access memory.
Merge remote-tracking branch 'ethereum/develop' into sol_strings

Conflicts:
	libsolidity/Types.cpp
VMFactory - a new way of creating VMs
Merge remote-tracking branch 'upstream/develop' into vm
Style fixes (mostly)
Catch exception by reference
Support empty strings.
VM::go detemplatized. Cleanups.
Swap literals to the end if optimizing.
Do not add at the end of the function selector "loop".
Test unexpected storage entries
Report wrong account address in case of unexpected storege key