Ability to require a plugin w/out code

[aubreypwd]

My dream here is that we can do something like wp plugin require <plugin-file> and it is suddenly a WDS required plugin. And, of course you can wp plugin unrequire <plugin-file> and it will disable it.

This would probably modify some mu-plugin to add to the filter, or it could actually distribute to the DB, but I'm not sure how that would get reflected via after a deploy, so maybe that's a bad idea.

Of course we could ditch the whole modify a PHP file thing, and instead maybe use a .file instead, e.g. .../plugins/.required which is simply a GLOB list of plugins that are required. Of course we would have PHP detect the files in that file and add them to the overall filter. Then this would offer these overall features:

1. Instead of adding a filter, you just create a plugins/.required file and track that in code vs the way we do it now with an mu-plugin

2. Running the wp commands will modify that file easily, adding and removing the required plugin to the file

Might be a good thing for 5ftf!