Misc. bug fixes

- add toString to all nodes to make it easier to identify nodes when debugging
- adding test to make sure web-inf is implicitly added
- fixing bug where multiple requests to the same URLs were being generated by the CSS tag handler and adding a test for this
- containsOrderedFragments now by default checks fragments only appear once in the text to prevent bugs like the one above. (added another spec test method that wont do this check for the odd use case where the text can appear more than once)