Ability for automatic reload for some config type

[yodasl]

It's a useful feature that for some type of config (file based or URL based) to have the system automatically reload the content/last modified date changed.
For file the last modified date should be enough and for URL based an eTag or if-modified-since header should do the trick.
When setting up such config, the API should accept a time reference for how frequently it should check for a reload? 30 seconds, 1 minute, 10 minutes, once a day etc...

[RichardHightower]

I like this idea.

I am going to keep the core small.

https://github.com/advantageous/konf-typesafe-config (this exists) used to use typesafe config with Konf
https://github.com/advantageous/konf-yaml-beans (this does not) going to write this to work with YAML
https://github.com/advantageous/konf-boon-json (this exists but is not checked in yet) boon JSON and Lax JSON.

https://github.com/advantageous/konf-reload (your etag feature will go here or in konf-boon-json)
https://github.com/advantageous/konf-consul-config (load config from consul)
https://github.com/advantageous/konf-etcd-config (load config from etcd)

I am going to add SmartProperty prop = config.getSmartProperty(...) or something like it to core konf.