Write only user modified values to the config file

[birdie-github]

This is driving me mad.

When I change anything using Wayfire Config Manager, all the settings from all the plugins and options are dumped to the config file.

It would be great if you wrote only the ones actually modified/changed by the user.

[soreau]

wcm uses wf-config API to modify the settings and only touches the options modified. So I think this would be a wf-config issue.