Move uptime / idletime from relative time to absolute time

[epsimatic]

Proposed changes:

• Add LastBoot sensor
• Add LastActive sensor
• Remove or disable by default UpTime sensor
• Remove or disable by default IdleTime sensor
• If ...Time sensors got disabled and not removed:
  • add a warning to documentation and/or runtime warning for people trying to turn these sensors on.

Rationale

As per this MR to Home-Assistant and around, we should avoid sensors that change values every second.

In order to optimize stability and performance of HomeAssistant, sensors should use only absolute time values (store the date of the event) and not relative time values (seconds from event) so the db value doesn't change each seconds.
"uptime" integration is one leftover, so to adhere to HomeAssistant development rules, the sensor is now changed to a timestamp.

[sleevezipper]

Thanks for creating an issue! This seems like a better way to do it.

[ChrisMancini]

I have made the necessary changes to convert UpTime/IdleTime to LastBoot/LastActive. I have a local branch with my modifications. What is the proposed process to submit a PR?

[sleevezipper]

Oh that's great @ChrisMancini! Thanks a lot!

I think the only way to submit a PR is to fork this repo, make the changes and push, and then create a PR from your repo.

[sleevezipper]

Thanks a lot for your contribution @ChrisMancini. It has been merged and will be in the next release.