* Foundational components for reading/processing Wattsi files into classes.
* Introducing tests for compliance with wattsi definitions.
- Several elements have been found to be missing from the code generator.
- A long-term strategy for dealing with obsolete elements will be needed. Should we remove and change the API? Or should we deprecate and leave in-place?
- Found one element that was accidentally added to the code generator but never used. Hopefully.
- Fixes will be applied in following commits.
* Added newer elements/tags and cleaned up invalid Tag class.
- Added DataTag.
- Added SlotTag and TemplateTag to support web components.
- Added global attributes to support web components.
- Removed GenerateTag. Accidentally introduced by string replacement in code generator.
* Upgrading revapi and maven plugin. Configured revapi to ignore removal of GenerateTag.
- The GenerateTag class was created accidentally. It does not have any representation in the HTML standard is should not be provided in this library.
