Add node filtering methods to the API about ox

[ohler55]

I would prefer to enhance the locate() and alocate() methods to support searching or filtering on Class as well as the current behavior. The text() method was a shortcut only because it is used so often. Other types are less frequently used from my experience. Have you looked at the locate() method on the Element class? What are you thoughts on expanding locate to handle Classes?

[ohler55]

I checked in some code for a 1.9.0 candidate. If you want the elements of a doc then try this

doc.locate('^Element')

comments try

doc.locate('^Comment')

[ohler55]

Please take a look at the changes. If you think it satisfies what you need close the issue. If I don't see a response I will assume the changes satisfy the issue.

[paulvt]

Ok, thanks for adding this. I haven't gotten around to change my application to use/test this yet, and I was waiting with a response for until after I used it. However, it looks good, thanks for adding this!

I miust admit I still like separate methods more coming from REXML (or both) as methods are cheap and make the code more readable, but I get it if you want to keep the API small.