Fixes and improvements to serialization.

There were multiple issues with comment and newline lexing.

Extended printing functions to support Strings with %S flag (captial 'S').
Allows for length detection. Also made it so that precision for strings is the string length.

test/SOA.cpp

@@ -118,9 +118,9 @@ void check_SOA()
 {
 	log_fmt("\ncheck_SOA:");
 	gen::init();
-	
+
 	Builder soa_test = Builder::open( "SOA.gen.hpp" );
-	
+
 	soa_test.print( parse_using( code(
 		using u16 = unsigned short;
 	)));

test/test.cpp

@@ -16,9 +16,9 @@ int gen_main()
 
 	// check_sanity();
 
-	check_SOA();
+	// check_SOA();
 
-	// check_singleheader_ast();
+	check_singleheader_ast();
 
 	return 0;
 }