Add basic scripting support.

- Fix certain bugs in ruby parser
- And a lot more cleanup/minor fixes.

src/internal/syntax/miniparser.cc

@@ -8,7 +8,7 @@ MiniParser::MiniParser(Language &lang, vase::Shard *vase, void *initial_state)
   void *state = lang.copy(start_state);
   std::vector<io::Token> tokens;
   std::vector<ParseEvent> events;
-  const uint64_t count = vase ? vase->lines + 1 : 0;
+  const uint64_t count = vase ? vase->lines + 1 : 1;
   lines.reserve(count);
   for (uint64_t i = 0; i < count; ++i) {
     it.next();