Remove std::.
Import directive.
Multi-source and multi-contract compiler.
Improved external interface for multi-source and multi-contract compilation.
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.
Comments and braces.
return when ciphertext empty
Evade networking crash.
Merge remote-tracking branch 'ethereum/develop' into sol_import

Conflicts:
	libsolidity/CompilerStack.cpp
	libsolidity/CompilerStack.h
	libsolidity/InterfaceHandler.cpp
	libsolidity/InterfaceHandler.h
	solc/main.cpp
	test/solidityJSONInterfaceTest.cpp
	test/solidityNatspecJSON.cpp
Merge pull request #558 from chriseth/sol_import

Solidity for multiple files and multiple contracts per file.
Compile fix.
Merge pull request #576 from chriseth/sol_compilefix

Compile fix. Over-the-shoulder review by @lefterisjp.
Calling functions of other contracts.
Const functions for ASTVisitor and const ASTPrinter.
Const AST visitor for the compiler.
Clear separation between ASTVisitor and ASTConstVisitor and more const specifiers.
More const cleanup.
Removed unused members.
using boost::program_options for argument parsing