Better composer integration

[aubreypwd]

Right now all composer packages are installed in /vendor. But features can have their own composer package dependancies and those don't need to go in /vendor at the root. E.g.:

In this example one of the features has it's own composer dependances.

Let's make sure the root composer.json also installs those by looping through the folders looking for composer.json and running pre/post install/update commands in those folders too.

[aubreypwd]

I think I'm going to leave these up to the developer instead. Maybe I can set them up as a component.