MFC 219717,220363:

• Add more details to the 'show battery' command including more raw capacity values, charge cycle count, temperature, and more detailed status.
• Add the ability to manage the state of write caching when the battery back-up is missing or dead. The current state of this field is reported in 'mfiutil cache <volume>' and can be adjusted via 'mfiutil cache <volume> bad-bbu-write-cache <enable|disable>'. This setting should generally be disabled to avoid data loss.