Raw.generate for ArrayList too

`JrJackson::Json.dump` should use `JrJackson::Raw.generate` for `Java::JavaUtil::ArrayList`. 

I also included tests for all base object support in `JrJackson::Json.dump`. 

Before applying this fix, calling `dump` on `ArrayList` would return `to.s` of the  `ArrayList`:
```ruby
JrJackson::Json.dump(Java::JavaUtil::ArrayList.new(["foo", 1])) #=> "[foo, 1]"
```
but what we want is ` "[\"foo\", 1]"`.
that's a good point! I guess it would make sense to capture all using the `List` and `Map` interfaces.