Refactor initial parsing stage

- Reduced the amount of state in the RawKeyword and ParserState classes.
 - RawKeyword class has normal constructor - remove init method.
 - The Rawxxx symbols are module private and the header files are not installed.
 - Removed several unused static methods from Rawxxx and ParserKeyword.

tests/parser/StarTokenTests.cpp

@@ -20,7 +20,8 @@
 #define BOOST_TEST_MODULE ParserTests
 #include <stdexcept>
 #include <boost/test/unit_test.hpp>
-#include <opm/parser/eclipse/RawDeck/StarToken.hpp>
+
+#include "src/opm/parser/eclipse/Parser/raw/StarToken.hpp"
 
 
 BOOST_AUTO_TEST_CASE(NoStarThrows) {