Simplify lexer significantly (remove all stateful lexing).

We are able to remove all state by simply passing NEWLINE through
as a token unconditionally (as opposed to only passing newline when
on a driective line as we did previously).
diff --git a/glcpp-parse.y b/glcpp-parse.y
index 29614fb..9883a6f 100644
--- a/glcpp-parse.y
+++ b/glcpp-parse.y
@@ -74,11 +74,17 @@
 		talloc_free ($1);
 	}
 |	directive_with_newline
+|	NEWLINE {
+		printf ("\n");
+	}
 |	content token {
 		_print_resolved_token (parser, $2);
 		talloc_free ($2);
 	}
 |	content directive_with_newline
+|	content NEWLINE {
+		printf ("\n");
+	}
 ;
 
 directive_with_newline: