Remove std::.
Import directive.
Multi-source and multi-contract compiler.
Improved external interface for multi-source and multi-contract compilation.
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
Merge remote-tracking branch 'ethereum/develop' into sol_import

Conflicts:
	libsolidity/CompilerStack.cpp
	libsolidity/CompilerStack.h
	solc/main.cpp
Renamed url to identifier and added some comments.
Replacing old cstyle enums with c++11 enums in natspec
Introducing VMFace - common VM interface
Merge pull request #566 from LefterisJP/natspec_cpp11_enums

Replacing old cstyle enums with c++11 enums in natspec
Use safe pointers in Executive
state log tests
fix stackoverflow in calldataload, codecopy, extcodecopy + some tests
avoid code repetition in vm
minor fix