ff-ap-timer: Add ap-timer and web-ap-timer from FFHO

[maurerle]

This makes it possible to add these well-known packages without adding a special package source for these.

It also allows to further develop the package in the future and adjust to eventually needed changes.

The ffac-ap-timer package can turn the client_radio on and off, but does not touch mesh or private wifi configuration.
The ffac-web-ap-timer package makes it possible to configure the schedule in the config mode.

closes #37

[grische]

@maurerle do you want to add this as ff- instead of ffac- as suggested recently in the chat? Or do you want to maintain this package in the future?

[grische]

Generally speaking, this version looks almost identical to the one we are already using with a few minor code improvements.

Where did you find that the original code was licensed under BSD 2?

[maurerle]

I did split this into three commits:

1. takes the old package
2. renaming to ff- and add license from https://github.com/FreifunkHochstift/ffho-packages/blob/master/LICENSE - and remove old migration
3. adjustments to pass luacheck

This can be merged from my side

[grische]

I guess you also want to rename this file here

[maurerle]

Thank you!

[maurerle]

I tested this package on a 7520 and it works good:

In the web settings, only the daily option is exposed.

This script changes the uci value on a daily base and writes the changes to flash, then restarts the wifi using wifi twice a day too.
This might be considered when using this package, but from the long history of this package I did not hear of devices which were broken due to this.

[grische]

Thanks