Refactor vault.data ns and add #uri support.

URIs can be represented by the #uri tag followed by the URI string.
Add some tests for vault.data.print ns.
Use map instead of for in 'for-files'.
Add printing tests for records and tagged values.

This includes fixing a bug detecting top-level tagged values when
running cloverage. Since cloverage instruments the code by attaching
metadata to forms, the vector literals had their ::tagged-value metadata
overwritten.
Added test for default print representations.

For example, printing a Java class instance which does not extend
TaggedValue.