Allow finer-grained skinning of home/overview page

[jonathaningram]

This allows skins to provide an array of panels for the home page. Panels are stacked vertically (as they already were) - however this PR just allows skins to provide whatever panels they like. Inside a panel, the skin can do what it wants. The cg skin retains the same behaviour and just renders some content tiles in a grid pattern. Note: I've moved these content tiles to the cg skin folder since they are specifically for cloud.gov.

I also added an import alias named dashboard so that skins can import components from the main dashboard source without having to rely on relative imports like ../../../../components/foo. An example use is:

import Panel from 'dashboard/components/panel.jsx';
import PanelGroup from 'dashboard/components/panel_group.jsx';

You can see cloud.gov.au's PR that matches this change: https://github.com/govau/ci-console/pull/1/files

I didn't want to make any more PRs until the prettier one is merged so I can avoid merge conflicts, but I wanted to get a start on this one.

[jonathaningram]

@jcscottiii ready for review.

[jcscottiii]

@jonathaningram i think a new .md doc for how to do skins should be created. that way someone in the future won't have to find this PR to do the same thing.

[jonathaningram]

@jonathaningram i think a new .md doc for how to do skins should be created. that way someone in the future won't have to find this PR to do the same thing.

@jcscottiii how about instead of writing a document, we include a "default" skin in this project? Here's my thinking:

I don't like writing documentation because I feel it becomes out of date with the code changes that are constantly coming in. Take the skins/cg/index.js doc stanza that I've recently removed. It was just annoying trying to keep it up-to-date. And nothing stopped me from forgetting to update the hard-coded code snippets in there that easily became out-of-date.

If we add a default skin, it will contain real code that must compile. Also, I'm not sure how you feel about this, but it can be the beginnings of a default non-cloud.gov skin that is used by default in this application. Again, we're the only users at the moment, but I read an issue somewhere in here saying that this should be a Cloud Foundry console, not a cloud.gov Cloud Foundry console. A default skin would help achieve that goal and also serve as documentation for how to do skins.

I do agree that guides like "How to create your custom cg-dashboard skin" are really useful, but I'm not sure if it's a good use of time at this stage.

[jcscottiii]

@jonathaningram i like love the idea of a default skin. i would love to move this into the cloudfoundry-community org and having a non cloud.gov skin would be great. now, how much work it would take to create such a skin, i'm not sure.

[jonathaningram]

@jonathaningram i like love the idea of a default skin. i would love to move this into the cloudfoundry-community org and having a non cloud.gov skin would be great. now, how much work it would take to create such a skin, i'm not sure.

@jcscottiii Awesome! I have just rebased this if you'd like to merge. Probably best to do the default skin in another PR so we can progress with this as it will be quite a large change.

[jcscottiii]

@jonathaningram thanks for this!! (i know we wanted #1252 in first but had questions there)