rework the Device Capabilities Properties section style (now Capability ...

...Data Interfaces) to use RFC terminology; use noLegacyStyle to remove redundant sections generated by the ReSpec tool

@hmin Please review the proposed normative change to interface DisplayUnit i.e. the DisplayUnit interface inherits availWidth, availHeight, width, height, colorDepth, and pixelDepth from the Screen interface [CSSOM]. Do you foresee any issues with this?