C++ namespace cleanup (except tests).

libsolidity/parsing/Parser.cpp

@@ -34,11 +34,9 @@
 #include <vector>
 
 using namespace std;
-using namespace langutil;
+using namespace solidity::langutil;
 
-namespace dev
-{
-namespace solidity
+namespace solidity::frontend
 {
 
 /// AST node factory that also tracks the begin and end position of an AST node
@@ -2088,4 +2086,3 @@ ASTPointer<ASTString> Parser::getLiteralAndAdvance()
 }
 
 }
-}