added dtd from ibatis.org and config to use during transform for thos…

[castlec]

I was forced to make some changes because my work machine doesn't have outside internet access. I needed to use cached dtd. I pulled all of the dtd from mybatis.org and created a new directory to reference them from. I have only referenced sql-map-2, leaving the identification of other publicId as an exercise to others when your code fails them :)

With the creation of a dtd directory, I also changed the reference to cached dtd in validation to pull from dtd directory rather than root.

[hazendaz]

don't think we need to merge this but rather than close and hide it if others need it, putting it in draft to prevent accidental merge otherwise. I probably would have merged after reviewing it but given it states it will cause users issues and they must figure that out, its not a good candidate to be merged in. Plus I'd like to hope 5 years later folks don't have this issue.

[harawata]

There is another report for the same (or similar) issue #44 , so I think this is worth merging.
I will try to do some cleaning up (e.g. remove duplicated or non-referenced DTD files) when I have time.