Introducing VMFace - common VM interface
Use safe pointers in Executive
fix stackoverflow in calldataload, codecopy, extcodecopy + some tests
avoid code repetition in vm
minor fix
even less code
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.