make use of C++ = default constructor declarations as well as more non-static member initialization syntax.

test/libsolidity/GasMeter.cpp

@@ -44,7 +44,6 @@ namespace test
 class GasMeterTestFramework: public SolidityExecutionFramework
 {
 public:
-	GasMeterTestFramework() { }
 	void compile(string const& _sourceCode)
 	{
 		m_compiler.reset(false);

test/libsolidity/SolidityABIJSON.cpp

@@ -38,8 +38,6 @@ namespace test
 class JSONInterfaceChecker
 {
 public:
-	JSONInterfaceChecker(): m_compilerStack() {}
-
 	void checkInterface(std::string const& _code, std::string const& _contractName, std::string const& _expectedInterfaceString)
 	{
 		m_compilerStack.reset(false);

test/libsolidity/SolidityNatspecJSON.cpp

@@ -39,8 +39,6 @@ namespace test
 class DocumentationChecker
 {
 public:
-	DocumentationChecker(): m_compilerStack() {}
-
 	void checkNatspec(
 		std::string const& _code,
 		std::string const& _contractName,

test/libsolidity/SolidityOptimizer.cpp

@@ -45,8 +45,6 @@ namespace test
 class OptimizerTestFramework: public SolidityExecutionFramework
 {
 public:
-	OptimizerTestFramework() { }
-
 	bytes const& compileAndRunWithOptimizer(
 		std::string const& _sourceCode,
 		u256 const& _value = 0,