Support for B4 beta, new core, overall structural improvements

This mainly addresses the fact that I didn't really know what the default renderer did, so I rewrote it completely adding some new features along the way:

• Validation (green or red outline + feedback)
• What should be handled at control level is controlled at control level (for manual rendering)
• A distinct and complete list of supported options and configurations
• Inline controls (buttons by default) are grouped in one line.
• Wiki, so you can customise this library
• Bug fixes and consistency fixes